If f(x)=4x^2-6 find all x such that f(x)= 106

Question

asked Jan 4, 2021 112k views

2 Answers

Aahnik · Answer 1 · 2021-01-09T04:41:55+0000

Answer:

$2\sqrt7,-2\sqrt7$

Explanation:

So we have the function:

f(x)=4x^2-6

And we want to find all x such that f(x) is 106. So, substitute 106 for f(x):

106=4x^2-6

Add 6 to both sides:

112=4x^2

Divide both sides by 4:

x^2=28

Take the square root of both sides:

$x=\pm√(28)$

Simplify the square root:

$x=\pm√(28)=\pm√(4\cdot 7)=\pm2\sqrt7$

So, those are the two values that will satisfy our requirement.

And we're done!