The question as is written :(adsbygoogle = window.adsbygoogle || []).push({});

Solve for x

5cosx-2= -0.72 ( 0 [tex]\leq[/tex] x [tex]\leq[/tex] 2[tex]\Pi[/tex] )

(The answer given is "1.31, 4.97".)

So, i done what seemed natural.

5cosx-2=-0.72

5cosx = 1.28

cosx = 1.28/5

cosx = 0.256

Firstly, i'm not even sure what unit my answer is supposed to be in. Since x is defined as Radians in the question, my answer of .256 = .256pi Radians (.256 of 180)?

Which should give solutions in the 1st & 4th quadrants.

All of the questions untill (there are a bunch similar to this) these ones have been in the form of, for example, 4=5 - tan2x (x in radians), which, as there are no decimals in the solution work out easy (pi/8, 5pi/8).. . why, if x is defined in Radians in the question, are the answers in decimals? I dont understand the principle of this when decimals are involved for some reasons.

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# Homework Help: Algebraic solution of Trig equation.

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