If \(f(x) = \begin{cases} x^2-4x & \quad \text{if } x≥2 \text{}\\ x

1.	If \(f(x) = \begin{cases} x^2-4x & \quad \text{if } x≥2 \text{}\\ x+2 & \quad \text{if } x<2 \text{} \end{cases}\), then f(5) is (a) -1 (b) 2 (c) 5 (d) 7
Answer» (c) 5 \(f(x) = \begin{cases} x^2-4x & \quad \text{if } x≥2 \text{}\\ x+2 & \quad \text{if } x<2 \text{} \end{cases}\) f(5) = 5² – 4(5) = 25 – 20 = 5 [For x = 5 take f(x) = x² – 4x]

If \(f(x) = \begin{cases} x^2-4x & \quad \text{if } x≥2 \text{}\\ x+2 & \quad \text{if } x<2 \text{} \end{cases}\), then f(5) is (a) -1 (b) 2 (c) 5 (d) 7

Answer»

(c) 5

\(f(x) = \begin{cases} x^2-4x & \quad \text{if } x≥2 \text{}\\ x+2 & \quad \text{if } x<2 \text{} \end{cases}\)

f(5) = 5² – 4(5) = 25 – 20 = 5

[For x = 5 take f(x) = x² – 4x]