What is #sin((7pi)/4)#?

3 Answers
May 1, 2018

#sin(7*pi/4)# = #-sqrt2/2#

Explanation:

#pi# in general equals to 3.142 in radian form or 180 degrees since #2pi# = 360 degrees.

To solve the eqn, we need to convert the #pi# into degrees.

#sin(7*pi/4)# = #sin(7*180/4)#
#sin(7*180/4)# = #sin(1260/4)#
#sin(1260/4)# = #sin(315)#
#sin(315)# = #-sqrt 2/2#

May 1, 2018

#-0.707#

Explanation:

#sin((7pi)/4)#

radians to degrees:-

#:.(7cancelpi^1)/cancel4^1xxcancel180^45/cancelpi^1=315^@#

#:.sin315^@=-0.707106781#

May 1, 2018

#rarrsin((7pi)/4)=-1/sqrt2#

Explanation:

#rarrsin((7pi)/4)=sin(2pi-pi/4)=-sin(pi/4)=-1/sqrt2#