Given f(x)= 8 − x^2, solve f(3x) = -28
First substitute (3x) into the equation for f(x), giving f(3x) = 8 - 9x2. This is then equal to -28 and so it is remains to solve the equation 8 - 9x2 = -28. This can be written as 9x2 = 36, dividing through by 9 gives x2 = 4 and so x = ±2.
GG
Answered by George G. • Further Mathematics tutor
4144 Views
See similar Further Mathematics GCSE tutorsRelated Further Mathematics GCSE answers
All answers ▸find the stationary point of the curve for the equation y=x^2 + 3x + 4
Differentiate y = x*cos(2x)
Express (7+ √5)/(3+√5) in the form a + b √5, where a and b are integers.
A curve has equation y = x^2 - 7x. P is a point on the curve, and the tangent to the curve at P has gradient 1. Work out the coordinates of P.