Question

Use the quadratic model y = -4x2 + 8x + 8 to predict y if x equals 100.

Answer 1

The value of y in
`y=-4 x^(2)+8 x+8` is -39192 when x is 100.

SOLUTION:

Given the quadratic equation is
`y=-4 x^(2)+8 x+8` --- eqn (1)

And we need to predict y when x =100

Let’s use the substitution method to solve this problem.

To get the value of y, substitute the x value in the equation (1)

`y=-4(100)^(2)+8 * 100+8`

`=-4 * 10000+800+8`

= -40000 + 808

y = -39192

Hence the value of y is -39192 when x is 100.