Question

If f(x) = 3x + 7, solve:
2[f(x^2)-5]

Answer 1

\[f(x ^{2})=3x ^{2}+7\]

Answer 2

\[2(f(x ^{2})-5)=2(3x ^{2}+7-5)=6x ^{2}+4\]

Answer 3

Thanks!

Answer 4

\[6x ^{2}+4=2(3x ^{2}+2)=0
so
3x ^{2}= -2
so
x ^{2}= -2/3
so
x_1,_2=+/- isqrt(2/3)= +/- (isqrt6)/3\]

Answer 5

so x_1,_2 = +/- (isqrt6)/3