Question

Find f(-3) for f(x)=2x^2+3x-4

Answer 1

Answer: 23

Explanation:

2(-3)^2+3(-3)-4 = -6^2+-9-4 = 36 - 13 = 23

Answer 2

The solution for f(-3) in f(x) =
`2 x^(2) + 3 x - 4` is 5

Solution:

From question, the given equation is,

f(x) =
`2 x^(2) + 3 x - 4` ------------------ eqn 1

We have to find the value of f(-3), hence put x = -3 in equation 1

By substituting x = -3 equation 1 becomes,

f(-3) =
`2 x^(2) + 3x - 4`

On solving the above equation, we get

f(-3) = 2(9) – 9 – 4

f(-3) = 18 – 9 – 4

f(-3) = 9 - 4 = 5

Hence the value of f(-3) = 5