How do you solve #sinx=-1/sqrt2#?

2 Answers
Apr 17, 2018

Around #-0.785398163397# radians.

Explanation:

We have:

#sinx=-1/sqrt2#

Apply inverse sine on both sides.

#=>x=sin^-1(-1/sqrt2)#

We find this to be around #-0.785398163397# radians.

Apr 17, 2018

#x =(pi + (2npi + pi/4)) or (2npi - (pi/4)), n in 0 to n#

Explanation:

#sin x = -(1/sqrt2)#

http://www.nabla.hr/TF-TrigFunctionsA4.htm

#"From above tables," sin x = -1/sqrt2 , x = 225^@ or 315^@#

#color(indigo)( " as sin is negative in third and fourth quadrants"#

#:. x = sin ^-1 (-1/sqrt2) = (180 + 45)^@ or (360-45)^@#

#x = (pi + (pi/4))^c or (2pi - (pi/4))^c#

Generalising,

#x =(pi + (2npi + pi/4)) or (2npi - (pi/4)), n in 0 to n#