Find the value of k if it is known that the graph of y=kk goes through A (4,-80) Please explain, I don’t get this concept and really need help!

Note: Consider the equation is instead of .

Given:

The graph of goes through A(4,-80).

To find:

The value of k.

Solution:

We have,

It is passes through the point A(4,-80). It means, the point satisfy the equation.

Putting x=4 and y=-80, we get

Divide both sides by 4.

Therefore, the value of k is -20.

answer:  

step-by-step explanation:

here x represents the height of the pole,

and, the height of the shadow of the pole is 12 feet.

also, the angle of elevation from the top of the pole is 40°,

therefore,

by the low of sine,

which is the required equation for finding the value of x,