last one! 50 points!

Answer:
sin theta = -2 sqrt(14)/15
Step-by-step explanation:
cos theta = adj / hyp
We can find the opp side by using the Pythagorean theorem
adj ^2 + opp ^2 = hyp^2
(-13)^2 + opp ^2 = 15^2
169 + opp ^2 = 225
opp ^2 = 225 -169
opp ^2 =56
Taking the square root of each side
sqrt( opp^2) = sqrt(56)
opp = sqrt(4 * 14)
opp = 2 sqrt(14)
Since we are in the third quadrant opp is negative
opp = -2 sqrt(14)
We know
sin theta = opp / hyp
sin theta = -2 sqrt(14)/15
Given that :
[tex] \frak {\cos( \theta_{1} ) = - \frac{13}{15} }[/tex]
To find :
[tex] \frak{ sin( \theta_{1} )}[/tex]
We know that cos θ is base/hypotentuse
So, here the base is -13 and the hypotentuse is 15
As we got the base and hypotentuse, perpendicular needs to be found out
Now, applying Pythagoras Theorem
According to Pythagoras theorem we know that :
Let us assume perpendicular be x
Putting the values we get
By transposing we get
sin θ formula : Perpendicular/Hypotentuse
[tex] \star \: \: \underline{ \overline{ \boxed{ \frak{ sin (\theta_{1})} = \frac{-2 \sqrt{14} }{15} }}}[/tex]
Hence, the answer is -2√14/15