It is a function because the input does not repeat itself.
The tangent line to <em>y</em> = <em>f(x)</em> at a point (<em>a</em>, <em>f(a)</em> ) has slope d<em>y</em>/d<em>x</em> at <em>x</em> = <em>a</em>. So first compute the derivative:
<em>y</em> = <em>x</em>² - 9<em>x</em> → d<em>y</em>/d<em>x</em> = 2<em>x</em> - 9
When <em>x</em> = 4, the function takes on a value of
<em>y</em> = 4² - 9•4 = -20
and the derivative is
d<em>y</em>/d<em>x</em> (4) = 2•4 - 9 = -1
Then use the point-slope formula to get the equation of the tangent line:
<em>y</em> - (-20) = -1 (<em>x</em> - 4)
<em>y</em> + 20 = -<em>x</em> + 4
<em>y</em> = -<em>x</em> - 24
The normal line is perpendicular to the tangent, so its slope is -1/(-1) = 1. It passes through the same point, so its equation is
<em>y</em> - (-20) = 1 (<em>x</em> - 4)
<em>y</em> + 20 = <em>x</em> - 4
<em>y</em> = <em>x</em> - 24
Your answer would be 4, because the equation for the circumference of a circle is π × diameter, so if you have 4 × π as the circumference, then 4 is the diameter.
I hope this helps!
Answer:
x=15 cm
Step-by-step explanation:
The two triangles in the diagram are:
ABC and BDC
First we have to find the third side (hypotenuse) of BDC so that we can use it to find the value of x.
Hypotenuse is the largest side of a triangle which is usually in front of the right angle.
So in BDC

Applying Pythagoras theorem:

Solving for triangle ABC

Applying Pythagoras theorem

Hence,
x=15 cm
Answer:
acute: 7, 9
right: 8, 10
obtuse: 5, 6
Step-by-step explanation:
When you have a number of identical calculations to do, it is convenient to do them in a spreadsheet. You only need to enter the formula once and copy it as many times as needed.
The attachment shows the "sum of squares" calculation and comparison to the square of the longest side. When the sum is too small, the longest side is longer than needed for a right angle, so the triangle is obtuse. When the sum is too great, the longest side is too short for a right angle, so the triangle is acute.
We have skipped the tedious arithmetic and shown the results in the attached table.