Question

if Alfa , beta are complementary angles sin Alfa=3/5 then cos Alfa cos beta - sin Alfa sin beta​

Answer 1

Answer:

11/25

Step-by-step explanation:

alpha will be referred to as 'a' and beta as 'b'

So according to question given,

Sin a = 3/5

Comparing to trigonometric ratios,

Opposite side = 3

Hypotenuse = 5

Using Pythagoras theorem, the adjacent side = 4

Therefore using trigonometric ratios,

cos a = 4/5

cos b = 4/5

sin a = 3/5

sin b = 3/5

Substituting into the question,

4/5 x 4/5 - 3/5 x 3/5

20/25 - 9/25

11/25

Answer 2

Answer:

sin Alfa =3/5

Perpendicular=3

Hypotenuse=5

Base ?

By Pythagoras Theoram

We will find the value of base

After that put the values in the equation