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Member Forums => Yoni's Math Forum => Topic started by: Probe on October 04, 2006, 03:18 PM

Title: small question
Post by: Probe on October 04, 2006, 03:18 PM
so this was on my calculus homework: differentiate 3 cos x. i know the derivative of cosx is -sinx, but im not sure how to write it with the 3. is it -3sinx or 3-sinx, is there a difference? or am i dong it wrong? thanks!
Title: Re: small question
Post by: rabbit on October 04, 2006, 07:01 PM
3 remains, as it is a coefficient.  It's -3sinx, since it is a coefficient.  If it was 3+cosx, the derivative would be -sinx (constants drop out).
Title: Re: small question
Post by: Rule on October 05, 2006, 01:19 PM
Quote from: Probe on October 04, 2006, 03:18 PM
so this was on my calculus homework: differentiate 3 cos x. i know the derivative of cosx is -sinx, but im not sure how to write it with the 3. is it -3sinx or 3-sinx, is there a difference? or am i dong it wrong? thanks!

Is there a difference between 3 - sin(x) and -3*sin(x)?  Of course!  Is there no difference between (-3)*sin(x) and (3)*(-sin(x))?  Of course!