Question

plz anyone solve this​

Answer 1

Step-by-step explanation:

sinQ+2cosQ=1

sinQ=1-2cosQ

2sinQ-cosQ= EQ 2

put sinQ=1-2cos Q in EQ 2 we have

2(1-2cos Q ) -cos Q =

2-4cos Q -cos Q =

2-3 cos Q =

cos Q= 2/3

DON'T FORGET TO MARK ME AS BRAIN LIST

Answer 2

Answer:

Consider the given equation.

sinθ+2cosθ=1 ……… (1)

On squaring both sides, we get

(sinθ+2cosθ)2=12

sin2θ+4cos2θ+4sinθcosθ=1

We know that

sin2θ=1−cos2θ

cos2θ=1−sin2θ

Therefore,

1−cos2θ+4(1−sin2θ)+4sinθcosθ=1

−cos2θ+4−4sin2θ+4sinθcosθ=0

−cos2θ−4sin2θ+4sinθcosθ=−4

4sin2θ+cos2θ−4sinθcosθ=4

(2sinθ−cosθ)2=4

2sinθ−cosθ=2

Hence, proved.