Find all solutions of the equation in the interval [0, 2π]. 5 cos^3 x = 5 cos x
5cos3x = 5cosxFirstly -5cosx from both sides and divide through by 5We have:cos3x-cosx = 0We can factorise this:cosx(cos2x - 1) = 0 For this to be true either:cosx = 0 or cos2x = 1for cosx = 0This occurs at pi/2 and 3pi/2.for cos2x = 1We have cosx = +/- 1 (do not forget to take +/- sqrt)This occurs at 0, pi, 2pi.Our solutions are:x = 0, pi/2, pi, 3pi/2, 2pi
GC
Related Maths A Level answers
All answers ▸Integration question 1 - C1 2016 edexcel
What is the area bound by the x-axis, the lines x=1 and x=3 and the curve y=3x^(2)-1/x ? Answer in exact form.
Find the x co-ordinates of the stationary points of the graph with equation y = cos(x)7e^(x). Give your answer in the form x = a +/- bn where a/b are numbers to be found, and n is the set of integers.
Differentiate the following equation: y = 2(x^3) - 6x