prove (1-sin x)/sec x = cos^3 x/1+sin x any trig people in the houseeeeee
On LHS, replace 1/sec(x) with cos(x). Multiply top and bottom of LHS by (1 + sin(x)) and simplify to get the RHS.
i have actually solved this working with both sides of the equation i just got lost in the steps a little bit so i was hoping someone could rework it
=(12−sin2x)1cosx(1+sinx) =cos2x×cosx(1+sinx)=cos3x1+sinx
how did we get this?
\[\frac{ 1-\sin(x) }{ \sec(x) } = (1 - \sin(x))\cos(x) = (1 - \sin(x))\cos(x) \times \frac{ (1+\sin(x)) }{ (1 + \sin(x)) } = ?\]
i have this all typed up i am sorry it wont copy and paste right
(1^2−sin^2x)/(1/cosx)(1+sinx)
(1 - sin(x)) * (1 + sin(x)) = 1^2 - (sin(x))^2 (because (a-b)(a+b) = a^2 - b^2 1^2 - (sin(x))^2 = cos^2(x)
then multiply both sides buy cosx to eliminate that sec in the demoninator
oh i think thats what i needed!
(1^2−sin^2x)/(1/cosx)(1+sinx) = cos^2(x) / { 1 / cos(x) * (1 + sin(x)) } = cos^3(x) / (1 + sin(x))
i get it, its the algebra that kills me like that.
alright.
great thanks!
any last words of wisdom ill take from you haha
You are welcome. Dividing by a fraction is same as multiplying by its reciprocal. Here dividing by (1/cos(x)) is same as multiplying by cos(x).
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