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Find all exact solutions on [0, 2π).

[tex]2tan^2(t) = 3 sec(t)[/tex]

I tried using some trig identities only to get lost or end up getting some complicated equation! Any help is very much appreciated, thank you :)

Respuesta :

Answer:

[tex]\displaystyle t=\frac{\pi}{3},\ t=\frac{5\pi}{3}[/tex]

Step-by-step explanation:

Trigonometric Equations

The given equation is

[tex]2tan^2t=3sect[/tex]

To solve the equation we must recall that

[tex]tan^2t=sec^2t-1[/tex]

Substituting into the given equation

[tex]2(sec^2t-1)=3sect[/tex]

Operating and rearranging

[tex]2sec^2t-3sect-2=0[/tex]

This is a second-degree equation in terms of sect. Factoring

[tex](sect-2)(2sect+1)=0[/tex]

This produces two solutions

[tex]\displaystyle sect=2,\ sect=-\frac{1}{2}[/tex]

Recalling

[tex]\displaystyle cost=\frac{1}{sect}[/tex]

The solutions are also expressed as

[tex]\displaystyle cost=\frac{1}{2},\ cost=-2[/tex]

since the magnitude of the cosine cannot be greater than 1, the only acceptable solution is

\displaystyle cost=\frac{1}{2}

Which has two possible angles in the interval [0,2\pi]

[tex]\boxed{\displaystyle t=\frac{\pi}{3},\ t=\frac{5\pi}{3}}[/tex]