The value of Sin(pie/2) plus Cos(2pie/3)?

Question

pleasee help.. ihave alot of questions to answer like 50 and i dont understand half of them..ill give best answers votings

Answer 1

Just evaluate this directly:

sin (π/2) + cos (2π/3)
1 - 1/2
1/2

Answer 2

Sin(pi/2) = 1
Cos(2pi/3) = -1/2
1 + (-1/2) = 1/2

Answer 3

The two answers above mine are correct. Here is why:

Sin pi/2 is the same as saying the sin of 90 in degree mode.

cos pi/2 is the same as saying cos of 90 in degree mode.

You can find any of these problems in a calulator by going to MODE and chaniging from degree to radian.

The value you are refferencing are all written on a refference table called the unit circle.

pi si the same as 180degrees

sin (pi/6)=1/2..the cos(pi/6)=(sqrt3)/2
sin (pi/4)=(sqrt2)/2 ..the cos (pi/4)=(sqrt2/2)
sin (pi/3)=(sqrt3)/2.. cos(pi/6)=1/2
sin (pi/2)=1.. cos(pi/2)=0
sin (2pi/3)=(sqrt3)/2.. cos(4pi/3)= -1/2
sin (3pi/4)=(sqrt2)/2.. cos (3pi/4)=-(sqrt2)/2
sin (5pi/6)=(1/2).. cos(5pi/6)=-(sqrt3)/2
sin (pi)=0.. cos(pi)=1
sin (7pi/6)=(-1/2).. cos(7pi/6)=-(sqrt3)/2
sin (5pi/4)=(-sqrt2)/2.. cos (3pi/4)=-(sqrt2)/2
sin (4pi/3)=(-sqrt3)/2.. cos(4pi/3)= -1/2
sin (3pi/2)=-1.. cos(3pi/2)=0
sin (5pi/3)=(-sqrt3)/2.. cos(4pi/3)= 1/2
sin (7pi/4)=(-sqrt2)/2.. cos(7pi/4)= (sqrt2/2)
sin (11pi/6)=(-1/2).. cos(11pi/6)= (sqrt3)/2

At 2pi all of the values revert to the table above. For ex sin2pi=sin0

I hope this helps!