FUNCTIONS 1

Find a linear function f(x) with gradient -10 which is such that f(5)=12.

        Solution.

m=-10, points = [5,12] and [x, f(x)]

m = y₂-y₁/x₂-x₁

-10 = f(x) – 12/x-5

f(x)-12=-10(x-5) [after cross multiply]

f(x)-12=-10x-50

f(x)=-10x+50+12

f(x)=-10x+62

Hence a  linear function is f(x) = -10x+62.

TRY THIS……….

Give out a linear function f(x) with

Gradient 5 and f(2)=14