Trigonometrical Ratios Class 9 OP Malhotra Exe-19A ICSE Maths Solutions Ch-19. Step by Step Solutions / Answer of Questions of OP Malhotra Maths. Visit official Website CISCE for detail information about ICSE Board Class-9 Mathematics.
Trigonometrical Ratios Class 9 OP Malhotra Exe-19A ICSE Maths Solutions Ch-19
| Board | ICSE |
| Publications | S Chand |
| Subject | Maths |
| Class | 9th |
| Chapter-19 | Trigonometrical Ratios |
| Writer | OP Malhotra |
| Exe-19A | How to Find Value of Trigonometrical Ratios |
| Edition | 2025-2026 |
Exercise- 19A
Trigonometrical Ratios Class 9 OP Malhotra Exe-19A ICSE Maths Solutions Ch-19
Que-1: Complete the following:
Sol: We know that tan θ = Perpendicular / Base
cos θ = Base / Hypotenuse ,
sin θ = Perpendicular / Hypotenuse
cot θ = 1/tanθ = Base / Perpendicular
sec θ = 1/cosθ = Hypotenuse / Base
and cosec θ = 1/sinθ = Hypotenuse / Perpendicular
Now, we shall complete the given
Que-2: From the figure, find the value of sin θ, cos θ, tan θ, sin2θ, cos2θ and tan2θ.
Sol: In the given figure,
AB = 5, BC = 12 and hyp. AC = 13 (units)
and ∠ACB = θ
∴ sin θ = AB/AC = 5/13
cos θ = BC/AC = 12/13
tan θ = AB/BC = 5/12
sin²θ = (5/13)² = 25/169
cos²θ = (12/13)² = 144/169
tan²θ = (5/12)² = 25/144
Que-3: From the figure, find the value of tanθ, tan2θ, tan3θ, sin2θ and cos3θ.
Sol: In the given figure, ∠ABC = θ and ∠C = 90°
AB = 5, BC = 3 and AC = 4
∴ tan θ = AC/BC = 4/3
tan²θ = (4/3)² = 16/9
tan³θ = (4/3)³ = 64/27
∵ sin θ = AC/AB = 4/5
∴ sin³θ = (4/5)³ = 64/125
and cos θ = BC/AB = 3/5
∴ cos³θ = (3/5)³ = 27/125
Que-4: In the figure, ∠OMP, ∠ORQ, ∠OQM are right angles. Write the values of the following t-ratios:
(a) sin RQM
(b) sin QMP
(c) sin OQR
(d) cos QMP
(e) tan RQM
(f) cot MOP
(g) sec ROQ
Sol: In the figure, ∠OMP, ∠ORQ and ∠OQM are right angles. Therefore,
(a) sin RQM = RM/QM
(b) sin QMP = PQ/PM
(c) sin OQR = OR/OQ
(d) cos QMP = QM/PM
(e) tan RQM = RM/QR
(f) cot MOP = OM/MP
(g) sec ROQ = OQ/OR
–: Trigonometrical Ratios Class 9 OP Malhotra Exe-19A ICSE Maths Solutions Ch-19 :—
Return to :– OP Malhotra S Chand Solutions for ICSE Class-9 Maths
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