arrow
arrow
arrow
If sin A=817\frac{8 }{17}178​​ then what is the value of cot A + sec A?
Question

If sin A=817\frac{8 }{17}​ then what is the value of cot A + sec A?

A.

211202\frac{1}{120}​​
​​

B.

31120\frac1{120 }​​

C.

41120\frac1{120 }​​

D.

51120\frac1{120 }​​

Correct option is B

Given:
sin A =817 \frac{8}{17}​​
Formula Used:
cotA=cosAsinA secA=1cosAcotA = \frac{\cos A}{\sin A}\\\ \\secA = \frac{1}{\cos A}​​
sin2A+cos2A=1\sin^2 A + \cos^2 A = 1​​
Solution:
cosA=1sin2A=1(817)2cosA=164289=225289=1517.\cos A = \sqrt{1 - \sin^2 A} = \sqrt{1 - \left(\frac{8}{17}\right)^2}\\\cos A = \sqrt{1 - \frac{64}{289}} = \sqrt{\frac{225}{289}} = \frac{15}{17}.​​

cotA=cosAsinA=1517817=158.\cot A = \frac{\cos A}{\sin A} = \frac{\frac{15}{17}}{\frac{8}{17}} = \frac{15}{8}.​​
secA=1cosA=1715.\sec A = \frac{1}{\cos A} = \frac{17}{15}.​​
cotA+secA=158+1715=225+136120=361120=31120\cot A + \sec A = \frac{15}{8} + \frac{17}{15} = \frac{225 + 136}{120} = \frac{361}{120}= 3 \frac1{120}​​
Alternate Method:
Sin A = 817=PH\frac{ 8}{17} = \frac PH​​

As we know, 8, 15, 17 are Pythagorean triplet, then Base = 15,

Cot A + Sec A

=> BP+HB\frac BP + \frac HB​​

158+1715=225+136120=361120=31120\rightarrow \frac{15}{8} + \frac{17}{15} = \frac{225 + 136}{120} = \frac{361}{120}= 3 \frac1{120}​​

Free Tests

Free
Must Attempt

SSC GD PYP (Held on 4 Feb 2025 S1)

languageIcon English
  • pdpQsnIcon80 Questions
  • pdpsheetsIcon160 Marks
  • timerIcon60 Mins
languageIcon English
Free
Must Attempt

Hindi Section Test 1

languageIcon English
  • pdpQsnIcon20 Questions
  • pdpsheetsIcon40 Marks
  • timerIcon12 Mins
languageIcon English
Free
Must Attempt

SSC GD Constable Full Mock Test 1

languageIcon English
  • pdpQsnIcon80 Questions
  • pdpsheetsIcon160 Marks
  • timerIcon60 Mins
languageIcon English
test-prime-package

Access ‘SSC CHSL Tier II’ Mock Tests with

  • 60000+ Mocks and Previous Year Papers
  • Unlimited Re-Attempts
  • Personalised Report Card
  • 500% Refund on Final Selection
  • Largest Community
students-icon
368k+ students have already unlocked exclusive benefits with Test Prime!
Our Plans
Monthsup-arrow