<h3>3
Answers:</h3>
A) y intercept is (0,3)
C) Axis of symmetry is x = -1
D) Vertex is (-1, 4)
So basically everything but choice B is true.
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Explanation:
Choice A is true because plugging in x = 0 leads to y = 3. Effectively, anything with an x goes away when x = 0 leaving that 3 behind. So finding the y intercept in this form is fairly fast.
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To check choices B through D, let's convert the equation into vertex form.
y = -1x^2 - 2x + 3 is in the form y = ax^2 + bx + c where
a = -1
b = -2
c = 3
The vertex is located at (h,k) such that h = -b/(2a)
Plug the values of 'a' and 'b' into the equation below
h = -b/(2a)
h = -(-2)/(2*(-1))
h = 2/(-2)
h = -1
The x coordinate of the vertex is x = -1
Then use this to find the y coordinate of the vertex
y = -1x^2 - 2x + 3
y = -1(-1)^2 - 2(-1) + 3
y = 4
The y coordinate of the vertex is 4, meaning k = 4
The vertex overall is (h,k) = (-1, 4)
This shows choice D is true, meaning choice B has to be false.
Choice C is true because the axis of symmetry is the x coordinate of the vertex. This is the vertical line that cuts the parabola into two mirrored halves. This vertical line always goes through the vertex.
Answer:
Step-by-step explanation:
Since Θ is in fourth quadrant then cosΘ > 0, as is secΘ
Given
sinΘ = - 
, then
cosΘ = 
= 
= 
= 
Hence
secΘ = 
=
Answer:
800 pennies
Step-by-step explanation:
Differentiate both sides of the equation.<span><span><span>d<span>dx</span></span><span>(<span>x3</span>+<span>y3</span>)</span>=<span>d<span>dx</span></span><span>(18xy)</span></span><span><span>d<span>dx</span></span><span>(<span>x3</span>+<span>y3</span>)</span>=<span>d<span>dx</span></span><span>(18xy)</span></span></span>Differentiate the left side of the equation.Tap for fewer steps...By the Sum Rule, the derivative of <span><span><span>x3</span>+<span>y3</span></span><span><span>x3</span>+<span>y3</span></span></span> with respect to <span>xx</span> is <span><span><span>d<span>dx</span></span><span>[<span>x3</span>]</span>+<span>d<span>dx</span></span><span>[<span>y3</span>]</span></span><span><span>d<span>dx</span></span><span>[<span>x3</span>]</span>+<span>d<span>dx</span></span><span>[<span>y3</span>]</span></span></span>.<span><span><span>d<span>dx</span></span><span>[<span>x3</span>]</span>+<span>d<span>dx</span></span><span>[<span>y3</span>]</span></span><span><span>d<span>dx</span></span><span>[<span>x3</span>]</span>+<span>d<span>dx</span></span><span>[<span>y3</span>]</span></span></span>Differentiate using the Power Rule which states that <span><span><span>d<span>dx</span></span><span>[<span>xn</span>]</span></span><span><span>d<span>dx</span></span><span>[<span>xn</span>]</span></span></span> is <span><span>n<span>x<span>n−1</span></span></span><span>n<span>x<span>n-1</span></span></span></span> where <span><span>n=3</span><span>n=3</span></span>.<span><span>3<span>x2</span>+<span>d<span>dx</span></span><span>[<span>y3</span>]</span></span><span>3<span>x2</span>+<span>d<span>dx</span></span><span>[<span>y3</span>]</span></span></span>Evaluate <span><span><span>d<span>dx</span></span><span>[<span>y3</span>]</span></span><span><span>d<span>dx</span></span><span>[<span>y3</span>]</span></span></span>.Tap for more steps...<span><span>3<span>x2</span>+3<span>y2</span><span>d<span>dx</span></span><span>[y]</span></span><span>3<span>x2</span>+3<span>y2</span><span>d<span>dx</span></span><span>[y]</span></span></span>Differentiate the right side of the equation.Tap for fewer steps...Since <span>1818</span> is constant with respect to <span>xx</span>, the derivative of <span><span>18xy</span><span>18xy</span></span> with respect to <span>xx</span> is <span><span>18<span>d<span>dx</span></span><span>[xy]</span></span><span>18<span>d<span>dx</span></span><span>[xy]</span></span></span>.<span><span>18<span>d<span>dx</span></span><span>[xy]</span></span><span>18<span>d<span>dx</span></span><span>[xy]</span></span></span>Differentiate using the Product Rule which states that <span><span><span>d<span>dx</span></span><span>[f<span>(x)</span>g<span>(x)</span>]</span></span><span><span>d<span>dx</span></span><span>[f<span>(x)</span>g<span>(x)</span>]</span></span></span> is <span><span>f<span>(x)</span><span>d<span>dx</span></span><span>[g<span>(x)</span>]</span>+g<span>(x)</span><span>d<span>dx</span></span><span>[f<span>(x)</span>]</span></span><span>f<span>(x)</span><span>d<span>dx</span></span><span>[g<span>(x)</span>]</span>+g<span>(x)</span><span>d<span>dx</span></span><span>[f<span>(x)</span>]</span></span></span> where <span><span>f<span>(x)</span>=x</span><span>f<span>(x)</span>=x</span></span> and <span><span>g<span>(x)</span>=y</span><span>g<span>(x)</span>=y</span></span>.<span><span>18<span>(x<span>d<span>dx</span></span><span>[y]</span>+y<span>d<span>dx</span></span><span>[x]</span>)</span></span><span>18<span>(x<span>d<span>dx</span></span><span>[y]</span>+y<span>d<span>dx</span></span><span>[x]</span>)</span></span></span>Rewrite <span><span><span>d<span>dx</span></span><span>[y]</span></span><span><span>d<span>dx</span></span><span>[y]</span></span></span> as <span><span><span>d<span>dx</span></span><span>[y]</span></span><span><span>d<span>dx</span></span><span>[y]</span></span></span>.<span><span>18<span>(x<span>d<span>dx</span></span><span>[y]</span>+y<span>d<span>dx</span></span><span>[x]</span>)</span></span><span>18<span>(x<span>d<span>dx</span></span><span>[y]</span>+y<span>d<span>dx</span></span><span>[x]</span>)</span></span></span>Differentiate using the Power Rule which states that <span><span><span>d<span>dx</span></span><span>[<span>xn</span>]</span></span><span><span>d<span>dx</span></span><span>[<span>xn</span>]</span></span></span> is <span><span>n<span>x<span>n−1</span></span></span><span>n<span>x<span>n-1</span></span></span></span> where <span><span>n=1</span><span>n=1</span></span>.<span><span>18<span>(x<span>d<span>dx</span></span><span>[y]</span>+y⋅1)</span></span><span>18<span>(x<span>d<span>dx</span></span><span>[y]</span>+y⋅1)</span></span></span>Multiply <span>yy</span> by <span>11</span> to get <span>yy</span>.<span><span>18<span>(x<span>d<span>dx</span></span><span>[y]</span>+y)</span></span><span>18<span>(x<span>d<span>dx</span></span><span>[y]</span>+y)</span></span></span>Simplify.Tap for more steps...<span><span>18x<span>d<span>dx</span></span><span>[y]</span>+18y</span><span>18x<span>d<span>dx</span></span><span>[y]</span>+18y</span></span>Reform the equation by setting the left side equal to the right side.<span><span>3<span>x2</span>+3<span>y2</span>y'=18xy'+18y</span><span>3<span>x2</span>+3<span>y2</span>y′=18xy′+18y</span></span>Since <span><span>18xy'</span><span>18xy′</span></span> contains the variable to solve for, move it to the left side of the equation by subtracting <span><span>18xy'</span><span>18xy′</span></span> from both sides.<span><span>3<span>x2</span>+3<span>y2</span>y'−18xy'=18y</span><span>3<span>x2</span>+3<span>y2</span>y′-18xy′=18y</span></span>Since <span><span>3<span>x2</span></span><span>3<span>x2</span></span></span> does not contain the variable to solve for, move it to the right side of the equation by subtracting <span><span>3<span>x2</span></span><span>3<span>x2</span></span></span> from both sides.<span><span>3<span>y2</span>y'−18xy'=−3<span>x2</span>+18y</span><span>3<span>y2</span>y′-18xy′=-3<span>x2</span>+18y</span></span>Factor <span><span>3y'</span><span>3y′</span></span> out of <span><span>3<span>y2</span>y'−18xy'</span><span>3<span>y2</span>y′-18xy′</span></span>.Tap for fewer steps...Factor <span><span>3y'</span><span>3y′</span></span> out of <span><span>3<span>y2</span>y'</span><span>3<span>y2</span>y′</span></span>.<span><span>3y'<span>(<span>y2</span>)</span>−18xy'=−3<span>x2</span>+18y</span><span>3y′<span>(<span>y2</span>)</span>-18xy′=-3<span>x2</span>+18y</span></span>Factor <span><span>3y'</span><span>3y′</span></span> out of <span><span>−18xy'</span><span>-18xy′</span></span>.<span><span>3y'<span>(<span>y2</span>)</span>+3y'<span>(−6x)</span>=−3<span>x2</span>+18y</span><span>3y′<span>(<span>y2</span>)</span>+3y′<span>(-6x)</span>=-3<span>x2</span>+18y</span></span>Factor <span><span>3y'</span><span>3y′</span></span> out of <span><span>3y'<span>y2</span>+3y'<span>(−6x)</span></span><span>3y′<span>y2</span>+3y′<span>(-6x)</span></span></span>.<span><span>3y'<span>(<span>y2</span>−6x)</span>=−3<span>x2</span>+18y</span><span>3y′<span>(<span>y2</span>-6x)</span>=-3<span>x2</span>+18y</span></span>Divide each term by <span><span><span>y2</span>−6x</span><span><span>y2</span>-6x</span></span> and simplify.Tap for fewer steps...Divide each term in <span><span>3y'<span>(<span>y2</span>−6x)</span>=−3<span>x2</span>+18y</span><span>3y′<span>(<span>y2</span>-6x)</span>=-3<span>x2</span>+18y</span></span> by <span><span><span>y2</span>−6x</span><span><span>y2</span>-6x</span></span>.<span><span><span><span>3y'<span>(<span>y2</span>−6x)</span></span><span><span>y2</span>−6x</span></span>=−<span><span>3<span>x2</span></span><span><span>y2</span>−6x</span></span>+<span><span>18y</span><span><span>y2</span>−6x</span></span></span><span><span><span>3y′<span>(<span>y2</span>-6x)</span></span><span><span>y2</span>-6x</span></span>=-<span><span>3<span>x2</span></span><span><span>y2</span>-6x</span></span>+<span><span>18y</span><span><span>y2</span>-6x</span></span></span></span>Reduce the expression by cancelling the common factors.Tap for more steps...<span><span>3y'=−<span><span>3<span>x2</span></span><span><span>y2</span>−6x</span></span>+<span><span>18y</span><span><span>y2</span>−6x</span></span></span><span>3y′=-<span><span>3<span>x2</span></span><span><span>y2</span>-6x</span></span>+<span><span>18y</span><span><span>y2</span>-6x</span></span></span></span>Simplify the right side of the equation.Tap for more steps...<span><span>3y'=−<span><span>3<span>(<span>x2</span>−6y)</span></span><span><span>y2</span>−6x</span></span></span><span>3y′=-<span><span>3<span>(<span>x2</span>-6y)</span></span><span><span>y2</span>-6x</span></span></span></span>Divide each term by <span>33</span> and simplify.Tap for fewer steps...Divide each term in <span><span>3y'=−<span><span>3<span>(<span>x2</span>−6y)</span></span><span><span>y2</span>−6x</span></span></span><span>3y′=-<span><span>3<span>(<span>x2</span>-6y)</span></span><span><span>y2</span>-6x</span></span></span></span> by <span>33</span>.<span><span><span><span>3y'</span>3</span>=−<span><span><span>3<span>(<span>x2</span>−6y)</span></span><span><span>y2</span>−6x</span></span>3</span></span><span><span><span>3y′</span>3</span>=-<span><span><span>3<span>(<span>x2</span>-6y)</span></span><span><span>y2</span>-6x</span></span>3</span></span></span>Reduce the expression by cancelling the common factors.Tap for more steps...<span><span>y'=−<span><span><span>3<span>(<span>x2</span>−6y)</span></span><span><span>y2</span>−6x</span></span>3</span></span><span>y′=-<span><span><span>3<span>(<span>x2</span>-6y)</span></span><span><span>y2</span>-6x</span></span>3</span></span></span>Simplify the right side of the equation.Tap for more steps...<span><span>y'=−<span><span><span>x2</span>−6y</span><span><span>y2</span>−6x</span></span></span><span>y′=-<span><span><span>x2</span>-6y</span><span><span>y2</span>-6x</span></span></span></span>Replace <span><span>y'</span><span>y′</span></span> with <span><span><span>dy</span><span>dx</span></span><span><span>dy</span><span>dx</span></span></span>.<span><span><span>dy</span><span>dx</span></span>=−<span><span><span><span>x2</span>−6y</span><span><span>y2</span>−6x</span></span></span></span>
