ConfusedWithMaths
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- Joined
- Feb 10, 2021
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- 6
[imath]\tan\alpha=-\frac{1}{3}[/imath] and [imath]\frac{\pi}{2}<\alpha<\pi[/imath] [imath]\implies[/imath] [imath]a=1[/imath], [imath]b=-3[/imath], & [imath]c=\sqrt{a^2+b^2}[/imath].View attachment 28403
I have let t = tan a for the first 3 parts (a, b and c), but I am confused with how I should do part d.
Thank you very much!Beer soaked ramblings follow.
[imath]\tan\alpha=-\frac{1}{3}[/imath] and [imath]\frac{\pi}{2}<\alpha<\pi[/imath] [imath]\implies[/imath] [imath]a=1[/imath], [imath]b=-3[/imath], & [imath]c=\sqrt{a^2+b^2}[/imath].
Just plug and chug using the 1st three of the Double-Angle Identities and the 3rd of the Half-Angle Identities.
View attachment 28406
Thank you!Use the inverse of the first formula.