Trig domains (1 Viewer)

highshill · Jul 12, 2017

Can someone please trig domain what I mean is
For example solve cos x root 3/ 2 in domain 0 deg less than or equal to X and less than or equal to 360

Sorry for writing in words

InteGrand · Jul 12, 2017

highshill said:
Can someone please trig domain what I mean is
For example solve cos x root 3/ 2 in domain 0 deg less than or equal to X and less than or equal to 360

Sorry for writing in words

$\noindent It means we are looking for the solutions to the equation $\cos x = \frac{\sqrt{3}}{2}$ that satisfy $0^{\circ}\leq x \leq 360^{\circ}$. If we didn't make this restriction on $x$, there would generally be other solutions to the equation (outside the given domain).$

highshill · Jul 12, 2017

What I get confused is how to use these identity eg
Theta
180- theta
My book just minuses the angles with the quadrant it is present in so I never got used to the above identities can some please explain what are they and how to use them please!
It will a heaps thanks

InteGrand · Jul 12, 2017

highshill said:
Can someone please trig domain what I mean is
For example solve cos x root 3/ 2 in domain 0 deg less than or equal to X and less than or equal to 360

Sorry for writing in words

$\noindent So for example, $x = 390^{\circ}$ is a solution to the equation $\cos x = \frac{\sqrt{3}}{2}$, but since $390^\circ$ isn't between $0^\circ$ and $360^\circ$, we are not going to include it as a solution to the given equation with the given domain. We are only looking for the solutions in the given domain (between $0^\circ$ and $360^\circ$).$

Trig domains (1 Viewer)

highshill

Active Member

InteGrand

Well-Known Member

highshill

Active Member

InteGrand

Well-Known Member

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