Trigonometry Formulas- Test Questions-ii

Question 11

Question:  

Answer:   

Question 12

Question:  

Answer:    Squaring and adding

Question 13

Question:   Evaluate:

Answer:   

Question 114

Question:   Evaluate:

Answer:   

Question 15

Question:   Evaluate:

Answer:   

Question 16

Question:   Evaluate:

Answer:   

Question 117

Question:  

Answer:   

Question 18

Question:   Prove that cot q - tan q = 2cot 2q.

Answer:   

Aliter:

Question 19

Question:  

Answer:   

Question 20

Question:   Prove that 4 sin 18^o cos 36^o = 1.

Answer:    LHS = 4 cos 72^o cos 36^o