Question 25 (Choice - 1) If tanβ‘π΄=3/4 , find the value of 1/sinβ‘π΄ +1/cosβ‘π΄
Given,
tan A = 3/4
(ππππ πππππ ππ‘π π‘π πππππ π΄)/(ππππ ππππππππ‘ π‘π πππππ π΄) = 3/4
π΅πΆ/π΄π΅ = 3/4
Let
BC = 3x & AB = 4x
We find AC using Pythagoras Theorem
In right triangle ABC
Using Pythagoras theorem
(AC)2 = (BC)2 + (AB)2
(AC)2 = (3x)2 + (4x)2
(AC)2 = 9x2 + 16x2
(AC)2 = 25x2
AC = β25π₯2
AC = 5x
Now,
sin A = (ππππ πππππ ππ‘π π‘π πππππ π΄)/π»π¦πππ‘πππ’π π
sin A = π΅πΆ/π΄πΆ
sin A = 3π₯/5π₯
sin A = π/π
cos A = (ππππ ππππππππ‘ π‘π π΄)/π»π¦πππ‘πππ’π π
cos A = π΄π΅/π΄πΆ
cos A = 4π₯/5π₯
cos A = π/π
Now,
π/πππβ‘π¨ +π/πππβ‘π¨ = 1/(3/5)+1/(4/5)
= 5/3+5/4
= (5 Γ 4 + 5 Γ 3)/(3 Γ 4)
= (20 + 15)/12
= ππ/ππ
Made by
Davneet Singh
Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo
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