If you flipped the graph y=x^2+2x-2 vertically, you would get the graph y=-(x^2+2x-2) this is True.
To prove that triangles TRS and SUT are congruent we can follow these statements:
1.- SR is perpendicular to RT: Given
2.-TU is perpendicular to US: Given
3.-Angle STR is congruent with angle TSU: Given.
4.-Reflexive property over ST: ST is congruent with itself (ST = ST)
From here, we can see that both triangles TRS and SUT have one angle of 90 degrees, another angle that they both have, and also they share one side (ST) ,then:
5.- By the ASA postulate (angle side angle), triangles TRS and SUT are congruent
Its the connection between those numbers
we know that
The formula of the surface area of the cone is equal to

where
SA is the surface area
r is the radius of the cone
l is the slant height
in this problem we have

Solve the formula for l

substitute the values

therefore
<u>the answer is</u>
The slant height is 
You forgot to put the options and the rest of the equation