Question #ce628

2 Answers
Jan 1, 2018

You need to be sure that your calculator is in radian mode.

#sin^-1(0.66) ~~ 0.720818760#

Solve for w by dividing by #0.0065#

#w = 0.720818760/0.0065#

#w ~~ 110.895 larr# close enough to what your teacher did.

Jan 1, 2018

w= 110.9

Explanation:

#sin^-1(0.66) = 0.0065w#

Be sure to set your calculator in "Rad" (radian) mode

#0.0065w =sin^-1(0.66) = .720819#

#w =.720819/.0065 = 110.8952...= 110.9 #

If you don't get the answer above, your calculator is probably not set in the radian mode.

Actually for # sintheta=a #, the general solution is:

#sintheta, sin(pi-theta), sin(2pi+theta),sin(3pi-theta), sin(4pi+theta)+...= a#

#rArr sin(npi+(-1)^ntheta)= a " for " n=0, 1, 2.."integer".#

#rArr npi+(-1)^ntheta= sin^-1a #

#theta = ( sin^-1a- npi)/(-1)^n = (-1)^n (sin^-1a- npi)#

with #n =0, 1, 2, 3, .. "integer".#*

Substitute # a =.66 and theta=0.0065w and solve " for " w#

#w =((-1)^n (.720819-npi))/.0065#

#w= 110.9, 372.43, 1339.07, ... for n=0, 1, 2, .."integer"#

*Note: #(-1)^n = (-1)^-n if n =0, 1, 2.. "integer"#