Question

Heya Mate ....


Prove that


$\sin( 90) = 1 \\ \\ class \: 9$
​

Answer 1

Answer:

Step-by-step explanation:

We know that:

Sin(2A)=2Sin(A)Cos(A)

Let 2A=90,

=> A=45.

Substituting it into the above equation:

=>Sin(2*45)=2Sin(45)Cos(45)

=>Sin(90)=2Sin(45)Cos(45).

Taking RHS:

2Sin(45)Cos(45)

=>2*1/2

=>1.

Hence proved!!

Answer 2

Solution :-

To Prove -

$= > \: sin(90) = 1$

Proving the above query algebraically :-

➨ Sin (A + B ) = Sin A Cos B + Cos A Sin B

➨ Sin (90) = Sin ( 45+45)

➨ Sin 45 Cos 45 + Cos 45 Sin 45

$= > \frac{1}{ \sqrt{2} } + \frac{1}{ \sqrt{2} } + \frac{1}{ \sqrt{2} } + \frac{1}{ \sqrt{2} }$

$= > \frac{1}{2} + \frac{1}{2}$

$= > 1$

Hence ,

Proved that sin(90) = 1