Question

If 2cosx+sinx=1 then find the value of 7cosx+6sinx

Answer 1

2cosx + sinx = 1

Let x = 90

2cos90 + sin90 = 2(0) + 1 = 1

7cosx + 6sinx

= 7cos90 + 6sin90

= 7(0) + 6(1)

= 6

Answer 2

Answer:

6

Step-by-step explanation

2 cos x = 1 - sin x

4 cos ²x = 1 + sin²x - 2 sinx

4 ( 1 - sin²x ) = 1 + sin²x - 2 sinx

5 sin²x - 2 sinx -3 = 0

sin x = 1

x = 90

7 cos x + 6 sin x = 6