Advertisements
Advertisements
प्रश्न
Find A, if 0° ≤ A ≤ 90° and 2 cos2 A – 1 = 0
उत्तर
2 cos2 A – 1 = 0
`=> cos^2A = 1/2`
`=> cosA = 1/sqrt(2)`
We know `cos 45^@ = 1/sqrt(2)`
Hence, A = 45°
APPEARS IN
संबंधित प्रश्न
If tan 2A = cot (A – 18°), where 2A is an acute angle, find the value of A
if `tan theta = 3/4`, find the value of `(1 - cos theta)/(1 +cos theta)`
if `cot theta = sqrt3` find the value of `(cosec^2 theta + cot^2 theta)/(cosec^2 theta - sec^2 theta)`
Show that : sin 42° sec 48° + cos 42° cosec 48° = 2
Find the value of x, if sin x = sin 60° cos 30° + cos 60° sin 30°
Find the value of x, if sin 3x = 2 sin 30° cos 30°
Use tables to find cosine of 65° 41’
Use trigonometrical tables to find tangent of 17° 27'
If \[\tan \theta = \frac{3}{4}\] then cos2 θ − sin2 θ =
Prove that:
\[\left( \frac{\sin49^\circ}{\cos41^\circ} \right)^2 + \left( \frac{\cos41^\circ}{\sin49^\circ} \right)^2 = 2\]
