

Maths Crash Course - Live lectures + all videos + Real time Doubt solving!
Examples
Example 2 Important
Example 3
Example 4
Example 5 Important
Example 6
Example 7 Important
Example 8 Important
Example 9 Deleted for CBSE Board 2023 Exams
Example 10 Important Deleted for CBSE Board 2023 Exams
Example 11 Important Deleted for CBSE Board 2023 Exams
Example 12 You are here
Example 13 Important
Example 14 Important
Example 15 Important
Last updated at Sept. 24, 2018 by Teachoo
Maths Crash Course - Live lectures + all videos + Real time Doubt solving!
Example 12 Express the ratios cos A, tan A and sec A in terms of sin A. cos A Since, cos2 A + sin2 A = 1 cos2 A = 1 โ sin2 A cos A = ยฑโ(1 โ๐ ๐๐2 ๐ด) Here, A is acute (i.e. less than 90ยฐ) & cos A is positive when A is acute So, cos A = โ(1 โ๐ ๐๐2 ๐ด) sec A sec A = ๐/๐๐จ๐ฌโกใ ๐จใ sec A = 1/โ(1 โ๐ ๐๐2 ๐ด) tan A We know that tan A = ๐๐๐โกใ ๐จใ/๐๐๐โกใ ๐จใ Putting value of cos A tan A = sinโกใ ๐ดใ/โ(1 โ ๐ ๐๐2 ๐ด)