Adv
mehak
  • 0
Newbie

4. If sin A = 9/41, compute cos A and tan A.

  • 0

Explain the question.

Which formula is used?

Class 10th, Rd sharma Trigonometric identies

Share

1 Answer

  1. Solution:

    R D Sharma Solutions For Class 10 Maths Chapter 5 Trigonometric Ratios ex 5.1 - 4

    Given that, sin A = 9/41 …………. (1)

    Required to find: cos A, tan A

    By definition, we know that

    sin A = Perpendicular/ Hypotenuse……………(2)

    On Comparing eq. (1) and (2), we get

    Perpendicular side = 9 and Hypotenuse = 41

    Let’s construct △ABC as shown below,

    And, here the length of base AB is unknown.

    Thus, by using Pythagoras theorem in △ABC, we get

    AC2 = AB2 + BC2

    412 = AB2 + 92

    AB2 = 412 – 92

    AB2 = 168 – 81

    AB= 1600

    AB = √1600

    AB = 40

    ⇒ Base of triangle ABC, AB = 40

    We know that,

    cos A = Base/ Hypotenuse

    cos A =AB/AC

    cos A =40/41

    And,

    tan A = Perpendicular/ Base

    tan A = BC/AB

    tan A = 9/40

    • 0
Leave an answer

Leave an answer

Browse

Choose from here the video type.

Put Video ID here: https://www.youtube.com/watch?v=sdUUx5FdySs Ex: "sdUUx5FdySs".

Captcha Click on image to update the captcha.

Related Questions