Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

Pages: **1**

**niharika_kumar****Member**- From: Numeraland
- Registered: 2013-02-12
- Posts: 1,021

If

,then prove that

It seems easy but I don't know why am I not able to solve it.

Pls help.....

friendship is tan 90°.

Offline

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,382

hi Niharika,

So I thought: replace every cos^2 with 1 - sin^2 and simplify. (I've left out some simplification steps ... you'll have to put them in yourself.)

Now to use the given equation:

Use this to simplify E by removing the highest power:

Go back to the given equation and use it again to remove the 4th power term:

therefore

QED.

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

Offline

**niharika_kumar****Member**- From: Numeraland
- Registered: 2013-02-12
- Posts: 1,021

wow

thanks.

friendship is tan 90°.

Offline

Pages: **1**