What should be the value of $p$ if the value of $3x^2 + 4x - p$ is 5, when (a) $x=-1$, (b) $x =1$?

Given:

The value of the expression $3x^2+4x-p$ is 5, when (a) $x=-1$, (b) $x =1$
To do:

We have to find the value of $p$.

Solution:

Let $f(x)=3x^2+4x-p$

(a) When $x=-1$,

$f(-1)=3(-1)^2+4(-1)-p=5$

$3-4-p=5$

$-1-5=p$

$p=-6$

(b) When $x=1$,

$f(1)=3(1)^2+4(1)-p=5$

$3+4-p=5$

$7-5=p$

$p=2$

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Updated on: 10-Oct-2022

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