Answer:
(4, -25)
Step-by-step explanation:
One way to answer this is to put the equation into vertex form.
f(x)= x^2 -8x -9 . . . . . given
Add and subtract the square of half the x-coefficient:
f(x) = x^2 -8x +(-8/2)^2 -9 -(-8/2)^2
f(x) = x^2 -8x +16 -25
f(x) = (x -4)^2 -25
Comparing this to the vertex form of a quadratic:
f(x) = a(x -h)^2 +k
we find that (h, k) = (4, -25). This is the vertex.
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<em>Alternate solution</em>
The line of symmetry for ...
f(x) = ax^2 +bx +c
is given by x = -b/(2a). For your given quadratic that line is ...
x = -(-8)/(2(1)) = 4
Evaluating f(4) gives the y-coordinate:
f(4) = 4^2 -8·4 -9 = -25
The vertex is (x, y) = (4, -25).
Answer:
See below.
Step-by-step explanation:
The domain refers to the x values used in the equation/graph. The line appears to go from -10 to 10 on the x-axis. The dots above -10 and 10 are not shaded in meaning those x values do not count towards the domain meaning we will use parenthesis instead of brackets for interval notation or no equal to signs in inequality notation.
Interval Notation: (-10, 10)
Inequality Notation: -10 < x < 10
The correct answer is x= -9. Hope this helps!!
is in quadrant I, so .
is in quadrant II, so .
Recall that for any angle ,
Then with the conditions determined above, we get
and
Now recall the compound angle formulas:
as well as the definition of tangent:
Then
1.
2.
3.
4.
5.
6.
7. A bit more work required here. Recall the half-angle identities:
Because is in quadrant II, we know that is in quadrant I. Specifically, we know , so . In this quadrant, we have , so
8.