## snickerzzz Group Title how do you find the sum of the series sigma n=0 ; 4 (cosn*pi) (3/4)^n one year ago one year ago

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1. RONNCC Group Title

use the equation maker

2. snickerzzz Group Title

$\sum_{n=0}^{\infty} 4 (\cos n \pi) (\frac{ 3 }{ 4 })^{n}$

3. RONNCC Group Title

are you sure it is till infinity?

4. snickerzzz Group Title

yes

5. TuringTest Group Title

Perhaps you can use some trig identities in conjunction with the ratio test.