Find: f (1), f (–1), f (0), f (2).
Answers:
If, x > 0, f (x) = 4x + 1
Substitute, x = 1
f (1) = 4(1) + 1
f (1) = 4 + 1
f (1) = 5
If x < 0, f(x) = 3x – 2
Substitute, x = –1
f (–1) = 3(–1) – 2
f (–1) = –3 – 2
f (–1) = –5
If, x = 0, f(x) = 1
Substitute, x = 0
f (0) = 1
If x > 0, f(x) = 4x + 1
Substitute, x = 2
f (2) = 4(2) + 1
f (2) = 8 + 1
f (2) = 9
∴ f (1) = 5
f (–1) = –5
f (0) = 1
f (2) = 9.