There are five ways including HL, AAS, ASA , SAS , and SSS.
I hope this helped! ( ^ω^ )
The answer is: 2 times taller than the person
Explanation: 6/15=height of lamp/(15+15); 6/15=height of lamp/30; height of lamp=(30/15)6=2×6, 2 times taller.
(Lamp is 12 feet tall)
So the question if find y'' for 4y=cos2x
First, find y by dividing by 4. y = cos2x/4
Then, take the first derivative. y' = -sin2x/2
Then, take the second dervative. y'' = -cos2x