2017年11月17日 · tan(45^@)=1 sin(45^@)=sqrt2/2 cos(45^@)=sqrt2/2 45^@ is a special angle, along with 30^@, 60^@, 90^@, 180^@, 270^@, 360^@. tan(45^@)=1 sin(45^@)=sqrt2/2 …

2015年9月12日 · Consider any right triangle with both its legs of same length. In this case both the other two angles would be 45 degrees each. Now, if both its legs are considered of unit …

Find the exact value of \cos 105^\circ using the fact that 105^\circ = 135^\circ - 30^\circ. Determine the value of cos (105) without using a calculator. Find the value of cos x - 4 tan x if …

cos 45^@ = sqrt(2)/2 The double angle formula for cos can be written: cos 2theta = cos^2 theta - sin^2 theta = 2cos^2 theta - 1 Given: cos 90^@ = 0 Let theta = 45^@ to get: 0 = cos 90^@ = …

2015年9月14日 · What is the value of #sin -45^@#? How do you find the trigonometric functions of values that are greater than #360^@#? How do you use the reference angles to find …

2018年4月6日 · Given: #cos 45^@# From the trigonometry cofunction identities: #cos theta = sin (90^@ - theta)# Let #theta = 45^@: " " cos 45^@ = sin (90^@ - 45^@) = sin 45^@#

2015年5月10日 · Cos 135° is an angle in the second quadrant. In the second quadrant, cos is negative. #Cos theta = x/r# #Cos 135 = cos(180-45) = -cos 45°#

2018年5月10日 · 0 Yes, it simplifies to give you zero. Now to make our lives easier, it would be better to turn the equation to: cos(45+a)cos(45-a) = sin(45-a)sin(45+a) This way we can …

2015年8月27日 · color(red)(cos(75)=(sqrt3 – 1)/(2sqrt2)) cos(75) = cos(45+30) The cosine sum identity is cos(A+B)= cosAcosB-sinAsinB ∴ cos(75)=cos(45)cos(30) – sin(45)sin(30 ...

2015年8月14日 · sin (60^@ + 45^@) = (sqrt(3) + 1)/(2sqrt(2)) Using the sine identity: sin (A +- B) = sin A cos B +- cos A sin B sin (60^@ + 45^@) = sin 60^@ cos 45^@ + cos 60^@ sin ...