Question

1. Cho hàm số: y = f(x) = x² + 4

 a, Tính f \(\left(-\dfrac{1}{2}\right)\); f(5)

 b, Tìm x khi f(x) = 10 

 

Answer 1

a: f(-1/2)=17/4

f(5)=29

Answer 2

\(a,f\left(-\dfrac{1}{2}\right)=\dfrac{1}{4}+4=\dfrac{17}{4}\\ f\left(5\right)=25+4=29\\ b,f\left(x\right)=10=x^2+4\Leftrightarrow x^2=6\Leftrightarrow\left[{}\begin{matrix}x=\sqrt{6}\\x=-\sqrt{6}\end{matrix}\right.\)