Question

A+B =90 cosB =3/5 then find value of sin A

Answer 1

The value of sin A would be 3/5

Given

• A+B =90
• cosB =3/5

To find

• value of sin A

Solution

we are provided with two angles A and B and some conditions and are asked to find the value of sin A.

A+B =90 (given)

or, B = 90 -A

cosB =3/5. (given)

substituting the value of B in this equation,

cos(90 - A) = 3/5

or, sin A = 3/5

From the Identity of trigonometric expressions, we know that cos of 90 - an angle would be sin of angle,

ie, cos(90-x) = sinx and

sin(90-x) = cosx

Therefore, the value of sin A would be 3/5

Answer 2

Answer:

The value of $sin A = \frac{3}{5}$.

Step-by-step explanation:

Given:

• $A+B =90$

• $cosB =\frac{3}{5}$

To find:

The value of $sin A$.

Step 1

Let, $A+B =90$

or, $B = 90 -A$

$cos B =\frac{3}{5}$.

Step 2

From the given equation,

substituting the value of $B$ in this equation, we get

$cos(90 - A) = \frac{3}{5}$

or,$sin A = \frac{3}{5}$

Step 3

From the Identity of trigonometric expressions,

we know that cos of $90 - a_{n}$ angle would be the sin of angle,

If $cos(90-x) = sin x$  and

$sin(90-x) = cos x$

Therefore, the value of $sin A$ would be $\frac{3}{5}$.

#SPJ2