Download App

Complementary Angles — MATHEMATICS STD 9 — Question

ICSE BoardEnglish MediumSTD 9MATHEMATICSComplementary Angles2 Marks
Question
Evaluate $: \sin 15^\circ \cos 15^\circ - \cos 75^\circ \sin 75^\circ $
✓

Answer

$\sin 15^\circ \cos 15^\circ - \cos 75^\circ \sin 75^\circ $
$= \sin(90^\circ - 75^\circ ) \cos15^\circ - \cos 75^\circ \sin (90^\circ -15^\circ )$
$= \cos 75^\circ \cos 15^\circ - \cos 75^\circ \cos 15^\circ $
$= 0.$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "[2 Mark Question Answer]" from Complementary Angles→Complementary Angles — all question types→MATHEMATICS STD 9 question papers→ICSE Board STD 9 question papers→ICSE Board question paper generator→

Similar questions

Evaluate $: \frac{\sec 75^{\circ}}{\operatorname{cosec} 15^{\circ}}$
→
If $\sec A=\operatorname{cosec} A$ and $0^{\circ} \angle A \angle 90^{\circ}$, state the value of $A$
→
Evaluate$: \tan (55^\circ - A) - \cot (35^\circ + A)$
→
Express the following as a vulgar fraction in simplest form:
$0.1 \overline{36}$
→
Find the area of a quadrilateral one of whose diagonals is $30\ cm$ long and the perpendiculars from the other two vertices are $19\ \ cm$ and $11\ cm$ respectively.
→
Draw a graph of each of the following equations$: 2x = 7$
→
Find the value of: $\log _{0.1} 10$
→
Verify the following:
$\cos 60^{\circ}=\left(1-2 \sin ^2 30^{\circ}\right)=\left(2 \cos ^2 30^{\circ}-1\right)$.
→
If $\sin \theta=\frac{\sqrt{3}}{2}$, find the value of $(\operatorname{cosec} \theta+\cot \theta)$.
→
Define the following term:
Class-size
→