<span> I am assuming you want to prove:
csc(x)/[1 - cos(x)] = [1 + cos(x)]/sin^3(x).
</span>
<span>If we multiply the LHS by [1 + cos(x)]/[1 + cos(x)], we get:
LHS = csc(x)/[1 - cos(x)]
= {csc(x)[1 + cos(x)]/{[1 + cos(x)][1 - cos(x)]}
= {csc(x)[1 + cos(x)]}/[1 - cos^2(x)], via difference of squares
= {csc(x)[1 + cos(x)]}/sin^2(x), since sin^2(x) = 1 - cos^2(x).
</span>
<span>Then, since csc(x) = 1/sin(x):
LHS = {csc(x)[1 + cos(x)]}/sin^2(x)
= {[1 + cos(x)]/sin(x)}/sin^2(x)
= [1 + cos(x)]/sin^3(x)
= RHS.
</span>
<span>I hope this helps! </span>
1. You have that the rule for a number pattern is add 4 and the <span>first term is 7.
2. Let's call "n" to the number in the line where each student is. Then, you can express this as below:
4n+7
3. So, you have:
Student N°1=4(1)+7=11
</span> Student N°2=4(2)+7=15
Student N°3=4(3)+7=19
Student N°4=4(4)+7=23
Student N°5=4(5)+7=27
Student N°6=4(6)+7=31
Student N°7=4(7)+7=35
Student N°8=4(8)+7=39
<span>
What number should Jenna say?
The answer is: 39</span>
The little squares at corner-B and corner-E were drawn there
to show that those are right angles.
You need to use the equation for adding fractions, which is
In this case, a=-1, b=3, c=-3, d=5.
simplify
answer: 
