Question

) If 2cos0 -11cos + 5 = 0 then find factor.​

Answer 1

Answer:

Let △=

∣

∣

∣

∣

∣

∣

∣

∣

C

1

6

1

C

1

0

1

C

∣

∣

∣

∣

∣

∣

∣

∣

=C(C

2

−1)−1(C−6)=C

3

−2C+6

Put C=2cosθ we get

△=(2cosθ)

3

−2(2cosθ)+6

=8cos

3

θ−4cosθ+6