Hi Varshini,
Please check Ex 8.3, 2 (ii) of Chapter 8 Class 10 Trigonometry here https://www.teachoo.com/1775/531/Ex-8.3--2---Show-that-(i)-tan-48-tan-23-tan-42-tan-67-=-1/category/Ex-8.3/
For solutions of all NCERT questions, please visit https://www.teachoo.com/maths/
Written on April 12, 2017, 8:55 p.m.