Introduction to Trigonometry Class 10 Worksheet Maths Chapter 8

True and False

Q1: cosA = 4/3 for some angle A.
Ans: False

Q2: tanA = sinA/cosA
Ans: True

Q3: secA = 1cosA, for an acute angle
Ans: True

Q4: sin60º = 2sin30º
Ans: False

Q5: SinA + CosA = 1
Ans: False

Short Answer Questions

Q6: Write the values cos 0°, cos 45°, cos 60° and cos 90°. What happens to the values of cos as angle increases from 0° to 90°?
Ans: cos0^∘ = 1
cos45^∘ = 1/√2
cos 60^∘ = 1/2
cos 90^∘ = 0
We can see that values of cos decreases as angle increases from 0° to 90°

Q7: Write the values of tan 0°,tan 30°, tan 45°, tan 60° and tan 90°. What happens to the values of tan as angle increases from 0° to 90°?
Ans:  tan 0^∘ = 0
tan 30^∘ = 1/√3
tan 60^∘ = √3
cos 90^∘ = undefined
We can see that values of cos decreases as angle increases from 0° to 90° 

 
Q8: If cosec A = √10 . find other five trigonometric ratios.
Ans: Given cosec A = √10


Now By Pythagoras theorem


Q9: The value of (sin 30^∘ + cos 30^∘) − (sin 60^∘ + cos 60^∘) is
Ans:


Q10: Evaluate the following: 2sin² 30^∘ − 3cos²45^∘ + tan²60^∘
Ans:


Q11: Evaluate:
cot²30^∘  − 2cos²60^∘ − 3/4sec²45^∘ − 4sec²30^∘
Ans:


Q12: Write the values of sin 0°, sin 30°, sin 45°, sin 60° and sin 90°. What happens to the values of sin as angle increases from 0° to 90°?
Ans:

We can see that values of sin increases as angle increases from 0° to 90°

Q13: If sin A = 3/5 .find cos A and tan A.
Ans:


Now By Pythagoras theorem


Q14: In a right triangle ABC right angled at B if sinA = 3/5. find all the six trigonometric ratios of C.
Ans:


Now By Pythagoras theorem



Q15: If sinB = 1/2 , show that 3 cosB − 4 cos³B = 0
Ans: