Download App

Trigonometric Identities — Mathematics STD 10 — Question

ICSE BoardEnglish MediumSTD 10MathematicsTrigonometric Identities2 Marks
Question
Without using trigonometric table, evaluate:
$
\frac{\sin 72^{\circ}}{\cos 18^{\circ}}-\frac{\sec 32^{\circ}}{\operatorname{cosec} 58^{\circ}}
$
✓

Answer

$
\begin{aligned}
& \frac{\sin 72^{\circ}}{\cos 18^{\circ}}-\frac{\sec 32^{\circ}}{\operatorname{cosec} 58^{\circ}} \\
& \Rightarrow \frac{\sin \left(90^{\circ}-18^{\circ}\right)}{\cos 18^{\circ}}-\frac{\sec \left(90^{\circ}-58^{\circ}\right)}{\cos e c 58^{\circ}} \\
& \Rightarrow \frac{\cos 18^{\circ}}{\cos 18^{\circ}}-\frac{\operatorname{cosec} 58^{\circ}}{\operatorname{cosec} 58^{\circ}}=1-1=0
\end{aligned}
$

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 Trigonometric Identities→Trigonometric Identities — all question types→Mathematics STD 10 question papers→ICSE Board STD 10 question papers→ICSE Board question paper generator→

Similar questions

The figure shows two circles which intersect at $A$ and $B$. The centre of the smaller circle is $O$ and lies on the circumference of the larger circle. iven that $\angle APB = a^o$. Calculate, in terms of $a^o$​​​​​​​, the value of: $\angle ADB.$
Give reasons for your answers clearly.
→
Points $A (-5, x), B (y, 7)$ and $C (1, -3)$ are collinear (i.e. lie on the same straight line) such that $AB = BC.$ Calculate the values of $x$ and $y.$
→
Evaluate the following $ :\left|\begin{array}{cc} 2 & 3 \\ -4 & 0 \end{array}\right|\left|\begin{array}{cc} 3 & -2 \\ -1 & 4 \end{array}\right| $
→
If $M =\left|\begin{array}{ll}8 & 3 \\ 9 & 7 \\ 4 & 3\end{array}\right|$ and $N =\left|\begin{array}{cc}4 & 7 \\ 5 & 3 \\ 10 & 1\end{array}\right|$ find $M + N$
→
The line through $A (- 2, 3)$ and $B (4, b)$ is perpendicular to the line $2a – 4y = 5.$ Find the value of $b.$
→
Solve equation by factorization : $(x – 4)^2 + 5^2 = 13^2$​​​​​​​
→
$D$ is a point on the side $BC$ of triangle $ABC$ such that angle $ADC$ is equal to angle $BAC$. Prove
that: $CA^2= CB \times CD$
→
A pair of dice is thrown. Find the probability of getting a sum of 10 or more, if 5 appears on the first die.
→
A card is drawn from a pack of 52 cards. Find the probability that the card drawn is:  a spade 
→
Find the remainder (without division) on dividing $f(x)$ by $(2x + 1)$ where $f(x) = 3x^3 – 7x^2 + 4x + 11$
→