हिंदी

State whether the statement is True or False? Also give justification. One value of θ which satisfies the equation sin4θ - 2sin2θ - 1 lies between 0 and 2π.

Advertisements
Advertisements

प्रश्न

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

One value of θ which satisfies the equation sin4θ - 2sin2θ - 1 lies between 0 and 2π.

विकल्प

  • True

  • False

MCQ
सत्य या असत्य
Advertisements

उत्तर

This statement is False.

Explanation:

Given equation is sin4θ – 2sin2θ – 1 = 0

sin2θ = `(-(-2) +- sqrt((-2)^2 - 4 xx 1 xx -1))/(2 xx 1)`

= `(2 +-  sqrt(4 + 4))/2`

= `(2 +-  sqrt(8))/2`

= `(2 +-  2sqrt(2))/2`

= `1 +- sqrt(2)`

∴ sin2θ = `(1 + sqrt(2))` or `(1 - sqrt(2))`

⇒ – 1 ≤ sin θ ≤ 1

⇒ sin2θ ≤ 1 but sin2θ = `(1 + sqrt(2))` or `(1 - sqrt(2))`

Which is not possible.

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 3: Trigonometric Functions - Exercise [पृष्ठ ६०]

APPEARS IN

एनसीईआरटी एक्झांप्लर Mathematics Exemplar [English] Class 11
अध्याय 3 Trigonometric Functions
Exercise | Q 72 | पृष्ठ ६०

वीडियो ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्न

Find the degree measure corresponding to the following radian measure `(use  pi = 22/7)`

`11/16`


Find the degree measures corresponding to the following radian measures (Use `pi = 22/7`)

`(5pi)/3`


A wheel makes 360 revolutions in one minute. Through how many radians does it turn in one second?


If in two circles, arcs of the same length subtend angles 60° and 75° at the centre, find the ratio of their radii.


Find the angle in radian through which a pendulum swings if its length is 75 cm and the tip describes an arc of length

21 cm


Find the degree measure corresponding to the following radian measure:
\[\frac{9\pi}{5}\]


Find the degree measure corresponding to the following radian measure:
\[\left( \frac{18\pi}{5} \right)\]


Find the radian measure corresponding to the following degree measure: 35°


Find the radian measure corresponding to the following degree measure: −56°


Find the radian measure corresponding to the following degree measure: 7° 30'


Find the magnitude, in radians and degrees, of the interior angle of a regular pentagon.


Find the magnitude, in radians and degrees, of the interior angle of a regular octagon.


The angle in one regular polygon is to that in another as 3 : 2 and the number of sides in first is twice that in the second. Determine the number of sides of two polygons.

 

The number of sides of two regular polygons are as 5 : 4 and the difference between their angles is 9°. Find the number of sides of the polygons.

 

A rail road curve is to be laid out on a circle. What radius should be used if the track is to change direction by 25° in a distance of 40 metres?

 

Find the distance from the eye at which a coin of 2 cm diameter should be held so as to conceal the full moon whose angular diameter is 31'.


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


If D, G and R denote respectively the number of degrees, grades and radians in an angle, the 


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


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°


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


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


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


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.

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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×