OP Malhotra Trigonometry Ratios Class-9 S.Chand ICSE Maths Ch-19

OP Malhotra Trigonometry Ratios Class-9 S.Chand ICSE Maths Ch-19. We Provide Step by Step Answer of Exe-19(a), Exe-19(b), Exe-19(c), Exe-19(d), with Chapter Test of S Chand OP Malhotra Maths . Visit official Website CISCE  for detail information about ICSE Board Class-9.

Board	ICSE
Publications	S. Chand
Subject	Maths
Class	9th
Chapter-19	Trigonometry Ratios
Writer	OP Malhotra
Topics	Solution of Exe-19(a), Exe-19(b), Exe-19(c), Exe-19(d), with Chapter Test
Academic Session	2021-2022

OP Malhotra Trigonometry Ratios Class-9 S.Chand ICSE Maths Ch-19

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-: Select Topics :-

Exercise-19(a)

Exercise-19(b)

Exercise-19(c)

Exercise-19(d)

Chapter Test

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Exercise-19

OP Malhotra Trigonometry Ratios Class-9 S.Chand ICSE Maths Ch-19

Trigonometric Ratios Definition :

It is defined as the values of all the trigonometric function based on the value of the ratio of sides in a right-angled triangle. The ratios of sides of a right-angled triangle with respect to any of its acute angles are known as the trigonometric ratios of that particular angle. Consider a right-angled triangle, right-angled

• sine: Sine of an angle is defined as the ratio of the side opposite(perpendicular side) to that angle to the hypotenuse.
• cosine: Cosine of an angle is defined as the ratio of the side adjacent to that angle to the hypotenuse.
• tangent: Tangent of an angle is defined as the ratio of the side opposite to that angle to the side adjacent to that angle.
• cosecant: Cosecant is a multiplicative inverse of sine.
• secant: Secant is a multiplicative inverse of cosine.
• cotangent: Cotangent is the multiplicative inverse of the tangent.

Trigonometry Applications :

Trigonometry is one of the most important branches of mathematics. Some of the applications of trigonometry are:

• Measuring the heights of towers or big mountains
• Determining the distance of the shore from the sea
• Finding the distance between two celestial bodies
• Determining the power output of solar cell panels at different inclinations
• Representing different physical quantities such as mechanical waves, electromagnetic waves, etc.

It is evident from the above examples that trigonometry has its involvement in a major part of our day-to-day life and much more. In most of the applications listed above, something was being measured and that is what trigonometry is all about.

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Exercise-19 (a)

 Trigonometry Ratios Class-9 S.Chand ICSE Maths Ch-19

Question 1:

Complete the following :

Figure see in your text book

Question 2:

From the figure, Find the value of sin θ, ………………. tan²θ

Question 3:

……………………

……………………

Question 4:

In the figure, …………….. of the following t-ratios :

(a) sin RQM

(b) sin QMP

(c) sin OQR

(d)………………

…………………….

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Exercise-19 (b)

OP Malhotra Trigonometry Ratios Class-9 S.Chand ICSE Maths Ch-19

Question 1:

Given that tan θ = 5/12 angle θ is an acute angle, find sin θ and cos θ.

Question 2:

If sin θ = 3/5 and ……………. find

(i) Cos θ

(ii) tan θ

Question 3:

…………………..

………………….

…………………..

Question 19:

Given 5 cos A – 12 sin A = 0 find the value of ……

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Exercise-19 (c)

 Trigonometry Ratios Class-9 S.Chand ICSE Maths Ch-19

Question 1:

(i) Prove that sin 60…………..

(ii) Without using trigonometric table find the ……………

Question 2:

If 0 ≤ x ≤ 90 , state the …………….. cos x.

Question 3:

……………………

………………….

………………….

Question 21:

The string of a kite is 150 m long and it makes an angle of 60 with the horizontal. Find the height of the kite from the ground.

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Exercise-19 (d)

 Malhotra Trigonometry Ratios Class-9 S.Chand ICSE Maths Ch-19

Without using trigonometric tables, evaluate questions 1 and 2.

Question 1:

(i) sin 16/cos74

……………………

Question 2:

(i) sin² 67 + sin² 23

……………………..

Question 3:

……………………

……………………..

………………………

Question 5:

(i) Find θ, if sin ……………………. an acute angle.

(ii) Find the value of ………… acute angles.

(iii) If A is an acute angle, solve…………………. cos 2A

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Chapter Test

 Trigonometry Ratios Class-9 S.Chand ICSE Maths Ch-19

Question 1:

If A = 30 and B = 60 then which of the following is/are correct /

…………………………

Question 2:

‘What is cot 15 cot 20 cot 70 cot 75 equal to ?

……………………………..

Question 3:

………………………

………………………

………………………..

Question 10:

In the figure a rocket is fired ……………… level as P. Calculate :

(i) The height of the rocket ……………

(ii) The horizontal distance …………….

— : End of Trigonometry Ratios OP Malhotra S Chand Solutions :–

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Return to :–   OP Malhotra S Chand Solutions for ICSE Class-9 Maths

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