Examples

Chapter 8 Class 10 Introduction to Trignometry
Serial order wise

### Transcript

Example 1 Given tan A = 4/3 , find the other trigonometric ratios of the angle A Given, tan A = 4/3 (π πππ πππππ ππ‘π π‘π πππππ π΄)/(π πππ ππππππππ‘ π‘π πππππ π΄) = 4/3 π©πͺ/π¨π© = π/π Let BC = 4x AB = 3x We find AC using Pythagoras Theorem In right triangle ABC Using Pythagoras theorem Hypotenuse2 = Height2 + Base2 (AC)2 = (BC)2 + (AB)2 (AC)2 = (4x)2 + (3x)2 (AC)2 = 16x2 + 9x2 (AC)2 = 25x2 AC = β25π₯2 AC = 5x Now, sin A = (π πππ πππππ ππ‘π π‘π πππππ π΄)/π»π¦πππ‘πππ’π π sin A = π΅πΆ/π΄πΆ sin A = 4π₯/5π₯ sin A = π/π Similarly, cos A = (π πππ ππππππππ‘ π‘π π΄)/π»π¦πππ‘πππ’π π cos A = π΄π΅/π΄πΆ cos A = 3π₯/5π₯ cos A = π/π Given, π­ππ§ π=π/π cosec A = 1/sinβ‘π΄ = 1/(4/5) = π/π sec A = 1/cosβ‘γ π΄γ = 1/((3/5) ) = π/π cot A = 1/tanβ‘π΄ = 1/(4/3) = π/π