FUNCTIONS 1

Find a linear function f(x) with gradient -6 which is such that f(5)=14.

Solution.

m=-6, points = [5,14] and [x, f(x)]

m = y₂-y₁/x₂-x₁

-6 = [f(x) – 14]/x-5

f(x)-14=-6(x-5)  [after cross multiplying]

f(x)-14=-6x+30

f(x)=-6x+30+14

f(x)=-6x+44

A  linear function is f(x) = -6x + 44.

TRY THIS……….

Give out a linear function f(x) with gradient -4 and f(5)=11.