I need help proving this identity

1/cosx - cosx = sinxtanx

5 answers

I have helped you with two of these now.
I think it is time for you to try them.
Hint:
on the LS, find a common denominator and add the two terms

Show me your steps and I will help you from there.
LS = 1/cosx - cosx/cosx
= 1-cosx/cosx
= sinx/cosx

I know this answer is extremely wrong. I have no idea what to do.
Reiny, are you still here. I need help quick. I'm really bad at trigonometric identities. I need help.
Ls = 1/cosx - cos^2 x/cosx
= (1-cos^2 x)/cox
= sin^2 x/cosx
= sinx sinx/cox
= sinx tanx
= RS

How can you change
1/cosx - cosx to 1/cosx - cosx/cosx ??
you can't just toss in an extra cosx at the bottom
that last term of cosx/cosx would reduce to 1
Have a tough time understanding calculus , in need of help please, appreciate you in advance <3

(i) Find the general solution of the Differential equation
𝑑2𝑦/𝑑𝑡2 = −4𝑡2 + 5𝑡 + 3
(ii)Hence, find the solution when 𝑡 = 0 , 𝑦 = 1 and 𝒅𝒚/𝒅𝒕= 1.