Question

Question #647eb

Answer 1

I can only give a few specific values for sin and cos. The corresponding values for tan and cot must be calculated from these, and additionnal values must be found with some sin and cos properties.

Explanation:

PROPERTIES
`cos(-x)=cos(x) ; sin(-x)=-sin(x)`
`cos(pi-x)=-cos(x) ; sin(pi-x)=sin(x)`
`cos(x)=sin(pi/2-x) ; sin(x)=cos(pi/2-x)`
`tan(x)=sin(x)/cos(x) ; cot(x)=cos(x)/sin(x)`

VALUES
`cos(0)=1` ; `sin(0)=0`
`cos(pi/6)=sqrt3/2` ; `sin(pi/6)=1/2`
`cos(pi/4)=sqrt2/2` ; `sin(pi/4)=sqrt2/2`
`cos(pi/3)=1/2` ; `sin(pi/3)=sqrt3/2`
`cos(pi/2)=0` ; `sin(pi/2)=1`

All these values and properties can be explained with the trigonometrical circle: