Answer:
Step-by-step explanation:
Sin2x=0,291
- Sin2x = 2Sinx * Cosx
Answer:
or 
Step-by-step explanation:
we know that
Applying the law of cosines

In this problem we have



substitute the values



Answer:
Answer is 3.3 simplfly is 3.3 have good day
Step-by-step explanation:
Both expression have the same denominator: 9x²-1. Thus it must not be 0.
9x²-1=(3x-1)(3x+1)=0, resulting x=+-1/3.
Restrictions: x in R\{-1/3, 1/3}
Adding those expressions:
E=(-x-2)/(9x²-1 ) + (-5x+4)/(9x²-1)=
(-x-2-5x+4)/(9x²-1)=(-6x+2)/(9x²-1)=
(-2)(3x-1)/(9x²-1)=-2/(3x+1)
E=-2/(3x+1)