FUNCTIONS 6

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

       Solution.

m=-6, points = [5,12] and [x, f(x)]

m = y₂-y₁/x₂-x₁

-6 = [f(x) – 12]/x-5

  

f(x)-12=-6(x-5) [after cross multiply]

f(x)-12=-6x+30

f(x)=-6x+30+12

f(x)=-6x+52

Hence A  linear function is f(x) = -6x+ 52.

TRY THIS……….

Give out a linear function f(x) with gradient -5 and f(6)=14