Let f : R → R be defined by Find (i) f(2) (ii) f(4) (iii) f( - 1) (iv) f( - 3).

Question

Philoid · Accepted Answer

i)f(2)

Since f(x) = x² - 2 , when x = 2

∴ f(2) = (2)² - 2 = 4 - 2 = 2

∴f(2) = 2

ii)f(4)

Since f(x) = 3x - 1 , when x = 4

∴f(4) = (3×4) - 1 = 12 - 1 = 11

∴f(4) = 11

iii)f( - 1)

Since f(x) = x² - 2 , when x = - 1

∴ f( - 1) = ( - 1)² - 2 = 1 - 2 = - 1

∴f( - 1) = - 1

iv)f( - 3)

Since f(x) = 2x + 3 , when x = - 3

∴f( - 3) = 2×( - 3) + 3 = - 6 + 3 = - 3

∴f( - 3) = - 3