FUNCTIONS 1C

Find a linear function f(x) with gradient -6 which is such that f(5)=12.

Solution.

m=-6, points = [5,10] and [x, f(x)]

m = y₂-y₁/x₂-x₁

-6 = [f(x) – 10]/x-5

f(x)-10=-6(x-5)  [after cross multiplying]

f(x)-10=-6x+30

f(x)=-6x+30+10

f(x)=-6x+40

A  linear function is f(x) = -6x + 40.

TRY THIS……….

Give out a linear function f(x) with gradient -8 and f(2)=12