Mathematics, 17.02.2020 00:47 herbal420medici
Find the EXACT value of cos(A+B) if sinA=−8/17 where A is in Quadrant III and sec B =−5/4 where B is in Quadrant II. Assume all angles are measured from standard position. cos(A+B) =
Answers: 1
![\bf sin(A)=\cfrac{\stackrel{opposite}{-8}}{\underset{hypotenuse}{17}}\qquad \impliedby \textit{let's find the \underline{adjacent side}} \\\\\\ \textit{using the pythagorean theorem} \\\\ c^2=a^2+b^2\implies \pm\sqrt{c^2-b^2}=a \qquad \begin{cases} c=hypotenuse\\ a=adjacent\\ b=opposite\\ \end{cases} \\\\\\ \pm\sqrt{17^2-(-8)^2}=a\implies \pm\sqrt{225}=a\implies \pm 15 = a\implies \stackrel{III~Quadrant}{-15=a} \\\\\\ therefore\qquad \qquad cos(A)=\cfrac{-15}{17} \\\\[-0.35em] ~\dotfill](/tpl/images/0512/7988/e164b.png)
![\bf sec(B)=\cfrac{\stackrel{hypotenuse}{5}}{\underset{adjacent}{-4}}\qquad \impliedby \textit{let's find the \underline{opposite side}} \\\\\\ \pm\sqrt{c^2-a^2}=b\implies \pm\sqrt{5^2-(-4)^2}=b\implies \pm\sqrt{9}=b \\\\\\ \pm 3 = b\implies \stackrel{II~Quadrant}{3=b}~\hfill cos(B)=\cfrac{\stackrel{adjacent}{-4}}{\underset{hypotenuse}{5}}~\hfill sin(B)=\cfrac{\stackrel{opposite}{3}}{\underset{hypotenuse}{5}} \\\\[-0.35em] ~\dotfill](/tpl/images/0512/7988/87c23.png)
Another question on Mathematics
Mathematics, 21.06.2019 18:00
The larger of two number is 4 less than twice the smaller number. the sum is 41. find the numbers
Answers: 2
Mathematics, 21.06.2019 19:30
Okay so i didn't get this problem petro bought 8 tickets to a basketball game he paid a total of $200 write an equation to determine whether each ticket cost $26 or $28 so i didn't get this question so yeahyou have a good day.
Answers: 1
Mathematics, 21.06.2019 19:30
Hi, can anyone show me how to do this problem? 100 points for this. in advance
Answers: 2
You know the right answer?
Find the EXACT value of cos(A+B) if sinA=−8/17 where A is in Quadrant III and sec B =−5/4 where B is...
Questions
Mathematics, 22.11.2019 05:31
Mathematics, 22.11.2019 05:31
Spanish, 22.11.2019 05:31
