Science (English Medium) Class 11 - CBSE Question Bank Solutions

If the angles of a triangle are in A.P., then the measures of one of the angles in radians is

The angle between the minute and hour hands of a clock at 8:30 is

At 3:40, the hour and minute hands of a clock are inclined at

If the arcs of the same length in two circles subtend angles 65° and 110° at the centre, than the ratio of the radii of the circles is

If OP makes 4 revolutions in one second, the angular velocity in radians per second is

A circular wire of radius 7 cm is cut and bent again into an arc of a circle of radius 12 cm. The angle subtended by the arc at the centre is

The radius of the circle whose arc of length 15 π cm makes an angle of \[\frac{3\pi}{4}\]  radian at the centre is

A circular wire of radius 3 cm is cut and bent so as to lie along the circumference of a hoop whose radius is 48 cm. Find the angle in degrees which is subtended at the centre of hoop.

Find the value of `sqrt(3)` cosec 20° – sec 20°

If θ lies in the second quadrant, then show that `sqrt((1 - sin theta)/(1 + sin theta)) + sqrt((1 + sin theta)/(1 - sin theta))` = −2sec θ

Find the value of tan 9° – tan 27° – tan 63° + tan 81°

Prove that `(sec8 theta - 1)/(sec4 theta - 1) = (tan8 theta)/(tan2 theta)`

If tan θ = `(-4)/3`, then sin θ is ______.

“The inequality `2^sintheta + 2^costheta ≥ 2^(1/sqrt(2))` holds for all real values of θ” 

The value of tan1° tan2° tan3° ... tan89° is ______.

The value of cos1° cos2° cos3° ... cos179° is ______.

Which of the following is correct?

[Hint: 1 radian = `180^circ/pi = 57^circ30^'` approx]

State whether the statement is True or False? Also give justification.

The equality sinA + sin2A + sin3A = 3 holds for some real value of A.

State whether the statement is True or False? Also give justification.

Sin10° is greater than cos10°

State whether the statement is True or False? Also give justification.

`cos  (2pi)/15 cos  (4pi)/15 cos  (8pi)/15 cos  (16pi)/15 = 1/16`