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 …

Answer to: Prove that cos(A + B) + sin(A - B) = 2sin(45 + A) cos(45 + B). By signing up, you'll get thousands of step-by-step solutions to your...

May 30, 2018 · -sin(45) In general, you can remember the fact that, d/dxsin(x)=cos(x) and d/dx cos(x)=-sin(x) So we have, d/dxcos(x) = -sin(x) => d/dxcos(45) = -sin(45) Hence the ...

May 10, 2018 · 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 …

Use a diagram to explain why {eq}\sin(135) = \sin (45) {/eq}, but {eq}\cos (135) \neq \cos (45) {/eq}. Sine and Cosine on the Unit Circle: The trigonometric functions sine and cosine are …

What is the sin cos and tan of 45? Trigonometry Right Triangles Trigonometric Functions of Any Angle. 1 ...

Find the exact values of the given trigonometric function without using a calculator. cos(cos^(-1)(0.8)) Find the exact values of the six trigonometric functions of the angle theta.cot …

Jan 26, 2017 · Solution: x=0^0 cos(x+45) + cos (x-45) =sqrt2 or cos x cos 45 cancel(- sinx sin45) + cosx cos45 cancel(+sinx sin45)=sqrt2 or 2 cosx cos45 =sqrt 2 or 2cosx *1/sqrt2 =sqrt 2 or 2 …

Use trig identity: sin (a - b) = sin a.cos b - sin b.cos a Trig table --> #sin 45 = sqrt2/2# and #cos 30 = sqrt3/2#

Feb 24, 2018 · Identities: #color(red)bb(cos(A+B)=cosAcosB-sinAsinB)# #color(red)bb(cos(A-B)=cosAcosB+sinAsinB)# #cos(x+45^@)=cosxcos(45^@)-sinxsin(45^@)#