====== Question 4, Review Exercise ====== Solutions of Question 4 of Review Exercise of Unit 09: Trigonometric Functions. This is unit of Model Textbook of Mathematics for Class XI published by National Book Foundation (NBF) as Federal Textbook Board, Islamabad, Pakistan. ====Go to ==== [[math-11-nbf:sol:unit09:Re-ex-p2|< Question 2 & 3 ]] [[math-11-nbf:sol:unit09:Re-ex-p4|Question 5 & 6 >]]