How do I solve the equation cos^2(x) - 4*cos(x) + (7 / 4 ) < 0?

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Homework Help Overview

The discussion revolves around solving the inequality cos²(x) - 4*cos(x) + (7 / 4) < 0, with the variable x belonging to the real numbers. The problem is situated within the context of precalculus mathematics.

Discussion Character

  • Exploratory, Problem interpretation, Assumption checking

Approaches and Questions Raised

  • Participants discuss potential methods for solving the inequality, including factoring and completing the square. There is a suggestion to substitute z for cos(x) to transform the problem into a quadratic equation.

Discussion Status

The discussion has seen some participants offering methods and clarifications, while others have expressed concerns about the categorization of the thread. There is acknowledgment of a resolution by one participant, though the details of that resolution are not provided.

Contextual Notes

There is a note regarding the misplacement of the thread in the forum, with participants indicating a lack of familiarity with the appropriate section for such questions. This may reflect on the assumptions and context in which the problem was presented.

JPC
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[SOLVED] Math - solving equation

Homework Statement



x belongs to Real numbers

Homework Equations



solving on paper
cos^2(x) - 4*cos(x) + (7 / 4 ) < 0


The Attempt at a Solution



no worthly attemps yet
 
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why don't you factorise it by using the completing the square thing or the ((-b)+or- (root(b^2) - 4ac) )/2a
...i think?
 
To follow up on sara_87's post, let z = Cos(x). Now you have a quadratic equation (inequality) which you can solve for z.

Next time you have a similar question please post it under Pre-calculus Math.
 
Why in the world is this in "other Sciences"?
 
well, i didnt see simply 'math' section , only saw 'calculus math' , didnt see 'Precalculus Mathematics' since i didnt have much time to post, sorry for wrong section. Next time ill know where to post for these types of questions

and btw, thanks for your help, resolved it easily now
 
Last edited:
Thread moved to Precalc Math.
 

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