Question

8. If 1 -cos B
2/5
. prove that 25 sin B (sin B - cos B) = 4.​

Answer 1

Answer:

1-cosB = 2/5

cos B = 3/5, so Sin B = 4/5

from question, 25 sin B (sin B - cos B)

25(4/5)(4/5 - 3/5)

25(4/5)(1/5)

=4

Hence Proved