please help

Question

please help

18jonea · Answer

attachment

18jonea · Answer

@518nad

18jonea · Answer

@mathmate

mathmate · Answer

One easy rule to remember:
Ratio of tangent does not have anything to do with the hypotenuse (opp/adj)
So any of the three ratios (sin, cos, tan) touching the hypotenuse can only be sine or cosine.
... and sine has opp/hypotenuse.

18jonea · Answer

oh so the answer is c @mathmate

mathmate · Answer

Please explain to me how you chose sin(45)=sqrt(2)/2 as the answer?

18jonea · Answer

because it is the hypotenuse and opposite @mathmate

solomonzelman · Answer

Yes, you are correct.

mathmale · Answer

"because it is the hypotenuse and opposite"      is unclear.  You are to find the ratio of side a to side c.  Side a is opposite the angle 45 degrees.

Thus, sin 45 degrees = (opp side) / (hypotenuse) = 1 / Sqrt(2).  Have to re-write the latter so as to eliminate the radical Sqrt(2) from the denominator.

mathmate · Answer

@18jonea
Yes, your explanation is valid for me, given the limited choices you have, 
and yes, your choice of answer is also correct.
Please, in the future, do not use the letters, but use the actual answer.  This will avoid confusion and also helps you reinforce your perception of the answer.