Question

23.
If sin x + sin^2 x= 1, show that cos^2 x + cos^4 x = 1

Answer 1

Answer:

sinx+sin

2 x=11−sin 2x=sinxcos 2 x=sinx

Thus,

cos 2 x+cos 4 x=sinx+sin 2 x=1

Answer 2

Answer:

A -B = 40 .................................1

B -C = 10 ..................................2

Therefore , we get,

A - C = 50...........................5

Adding 2 and 5, we get,

2.........B - C = 10

5.........A - C = 10

=> A + B = 60..........................6

Adding 1 and 6 , we get,

1...............A - B = 40

6..............A + B = 60

Therefore ,

A = 100

Equating on eq. 1, we get,

A - B = 40

100 - B = 40

B = 60

Equating on eq.2 , we get,

B - C = 10

60 - C = 10

C= 50