If 13sinx+5=0 and x�[0;270],determine witout the use of a calculator,the value of sin2x
2 answers
If you really want the help of an expert in this subject, you'll follow directions and put the SUBJECT in the School Subject box.
13sinx+5=0
sinx = -5/13
sinx is negative in QIII,QIV, but we want the QIII value.
so, cosx = -12/13
sin2x = 2sinx cosx = 2(-5/13)(-12/13) = 120/169
sinx = -5/13
sinx is negative in QIII,QIV, but we want the QIII value.
so, cosx = -12/13
sin2x = 2sinx cosx = 2(-5/13)(-12/13) = 120/169