Question

Plz answr it early so early if son thetha (2a+45)=cos (30-a) where ois less than 2a+45lessthan 90

Answer 1

Your question needs few corrections.

Correct Question :  if sin(2a+45)=cos(30-a) where is less than 2a+45 less than 90

Answer:

Value of a is 15.

Step-by-step explanation:

Given,

= >  sin( 2a + 45 ) = cos( 30 - a )

From the identities of trigonometry, we know that sinA can be written as cos( 90 - A ). So consider ( 2a + 45 ) as A and write sine of 2a + 45 in terms of cosine.

= >  cos[ 90 - ( 2a + 45 ) ] = cos( 30 - a )

= >  cos( 90 - 2a - 45 ) = cos( 30 - a )

= >  cos( 45 - 2a ) = cos( 30 - a )

Now, cosine of both the angles( 45 - 2a and 30 - a ) is equal, 45 - 2a and

30 - a are also equal .

= >  45 - 2a = 30 - a

= >  - 2a + a = 30 - 45

= >  - a = - 15  

= >  a = 15