Advertisements
Advertisements
प्रश्न
Write the value of cos1° cos 2°........cos180° .
Advertisements
उत्तर
Cos 1° cos 2° … cos 180°
= cos 1° cos 2° … cos 90° … cos 180°
= cos 1° cos 2° … 0 … cos 180°
= 0
APPEARS IN
संबंधित प्रश्न
Prove the following identities:
`( i)sin^{2}A/cos^{2}A+\cos^{2}A/sin^{2}A=\frac{1}{sin^{2}Acos^{2}A)-2`
`(ii)\frac{cosA}{1tanA}+\sin^{2}A/(sinAcosA)=\sin A\text{}+\cos A`
`( iii)((1+sin\theta )^{2}+(1sin\theta)^{2})/cos^{2}\theta =2( \frac{1+sin^{2}\theta}{1-sin^{2}\theta } )`
Evaluate
`(sin ^2 63^@ + sin^2 27^@)/(cos^2 17^@+cos^2 73^@)`
Evaluate without using trigonometric tables:
`cos^2 26^@ + cos 64^@ sin 26^@ + (tan 36^@)/(cot 54^@)`
Prove the following trigonometric identities.
`tan theta + 1/tan theta = sec theta cosec theta`
Prove the following trigonometric identities.
if `T_n = sin^n theta + cos^n theta`, prove that `(T_3 - T_5)/T_1 = (T_5 - T_7)/T_3`
If cos θ + cos2 θ = 1, prove that sin12 θ + 3 sin10 θ + 3 sin8 θ + sin6 θ + 2 sin4 θ + 2 sin2 θ − 2 = 1
Prove that:
`1/(sinA - cosA) - 1/(sinA + cosA) = (2cosA)/(2sin^2A - 1)`
Prove that:
`cosA/(1 + sinA) = secA - tanA`
Write the value of ` sec^2 theta ( 1+ sintheta )(1- sintheta).`
If `sqrt(3) sin theta = cos theta and theta ` is an acute angle, find the value of θ .
Prove that:
Sin4θ - cos4θ = 1 - 2cos2θ
Write True' or False' and justify your answer the following :
The value of \[\sin \theta\] is \[x + \frac{1}{x}\] where 'x' is a positive real number .
Prove the following identity :
`(1 + sinA)/(1 - sinA) = (cosecA + 1)/(cosecA - 1)`
Prove the following identity :
`(sinA + cosA)/(sinA - cosA) + (sinA - cosA)/(sinA + cosA) = 2/(2sin^2A - 1)`
Prove the following identity :
`(secA - 1)/(secA + 1) = sin^2A/(1 + cosA)^2`
Find x , if `cos(2x - 6) = cos^2 30^circ - cos^2 60^circ`
Without using trigonometric identity , show that :
`cos^2 25^circ + cos^2 65^circ = 1`
If cosθ = `5/13`, then find sinθ.
If A = 30°, verify that `sin 2A = (2 tan A)/(1 + tan^2 A)`.
Prove that `(1 + tan^2 A)/(1 + cot^2 A)` = sec2 A – 1
