Question

Find the smallest positive number x such that

cosine squared ⁡ x minus 1.3cosine ⁡ x plus 0.42equals 0

Answer 1

\[\cos ^2x-1.3\cos x+0.42\]

Answer 2

i really dont know what to do

Answer 3

@jim_thompson5910 @campbell_st Hello i was wondering if you can help me with this concept

Answer 4

let z = cos(x)

square both sides to get z^2 = cos^2(x)

Answer 5

solve \[\Large z^2 - 1.3z + 0.42 = 0\] for z. Then use the solutions in terms of z to get the solutions in terms of x.