wiz-icon
MyQuestionIcon
MyQuestionIcon
2
You visited us 2 times! Enjoying our articles? Unlock Full Access!
Question

How many of following are matched correctly

Column AColumn B1. Sin 780a.322. tan 1485b.13. Cos 1350c.14. Sec (1920)d.25. tan 2340e.06. cosec (765)f.27. Cot 600g.38. Sin 3105h.129. Sin (3105)i.1210. Cos 480j.12
___

Open in App
Solution

Let's find the values of each trigonometric function.

(1).Sin 780

If we add 360 to an angle, it gives the same effective angle or by rotating the radius by 360, we reach the same position.

780 can be written as (2 × 360 + 60)

Sin (2 × 360 + 60) = sin 60 = 32 (correctly matched)

2.tan1485 = tan (4 × 360 + 45)

= tan 45 = 1 (Not correctly matched)

3.Cos 1350 = cos (3 × 360 + 270)

= cos 270 = cos (360 - 90)

= cos 90 = 0 (Not correctly matched)

4.Sec (-1920) = sec 1920 {sec (-θ) = sec θ}

Sec (5 × 360 + 120) = sec 120

= sec (180-60) = - sec 60 = -2 (correctly matched)

5.tan 2340 = tan (6 × 360 + 180) = tan 180 = 0 (correctly matched)

6. cosec(-765) = - cosec 765 = -cosec(2 × 360 + 45)

= -cosec 45 = 2(Not correctly matched)

7. Cot 600 = Cot(360 + 240) = cot240

= cot(180 + 60) = cot 60 = 13 (Not correctly matched)

8. Sin 3105 = sin (8 × 360 + 225) = sin(225)

= sin (180 + 45) = -sin 45 = 12 (Correctly matched)

9. Sin(-3105) = -sin 3105 = (12) = 12(Correctly matched)

10. Cos 480 = cos(360 + 120) = cos 120

= cos(180 - 60) = -cos60 = 12 (Not Correctly matched)

So, 5 values are correctly matched.


flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Trigonometric Functions in a Unit Circle
MATHEMATICS
Watch in App
Join BYJU'S Learning Program
CrossIcon