Question

Cos11+sin11/cos11-sin11=tan56 prove using trigonometric formula.

Answer 1

Given that ⇒  Cos 11 + $\frac{sin 11}{cos 11} - sin 11$ = tan 56

Solution - 

⇒Cos 11 + $\frac{sin 11}{cos 11} - sin 11$

⇒ We have to divide the numerator and denominator by  cos 11 .

We get after dividing = 1 + tan $\frac{11}{1} - 1 tan11$

Since tan 45 = 1 
By substituting the value of 1 in numrator we got ....

⇒ tan 45 + tan$\frac{11}{1}$ - tan 45 tan 11
By using tan ( a + b ) 

We get,
⇒ tan ( 45 + 11 )
⇒ tan 56

Hence Prooved