How to find the values of tan135 and sin225 degrees?

Hello

Use the addition formulas : 135 = 90 + 45

and 225 = 180 + 45

tan(π/2 + x) = -1/tan(x)

sin(π + x) = - sin(x)

you know that tan 45° = 1

and that sin 45° = √2/2

Hope it helped

Bye !

we can find the value of tan135 and sin225 by using calculator or by mathematical method,the mathematical method is that we can write the tan135=tan(180-45)=-tan45=-1 and the value of sin225 =sin(270-45)=-sin45=-0.7

Its very easy. Just use formulae

tan135=tan(180-45)=(tan 180-tan 45)/(1+tan180*tan45)=(0-1)/(1+0)=-1

sin225=sin(270-45)=sin270 *cos45-cos270*sin45=-1/Root2=-0.70710678

tan135 = tan( 90+ 45)

= - tan45

= -1 ANSWER========================================================================

sin 225 = sin( 180+ 45)

= - sin45

= - 1/sqrt2 ANSWER

use sum or difference of trigonometric functions

tan 135 = tan (180 - 45)

tan (180-45) = (tan 180 - tan 45) / (1 + tan 180 * tan 45)

= (0 - 1) / (1 + 0 * 1)

= -1 / 1

= -1 . . .answer

sin 225 = sin (180 + 45)

sin (180 + 45) = sin 180 * cos 45 + cos 180 * sin 45

= 0*(√2/2) + (-1)*(√2/2)

= 0 - √2/2

= -√2/2 . . . answer

tan (180-45) which is -tan45 and sin (180+45) -sin45