Math & Data Science Q&A - Get answers from our AI that are verified by human experts
First time here? Checkout the FAQs!
x

*Math Image Search only works best with zoomed in and well cropped math screenshots. Check DEMO

0 like 0 dislike
8 views
Expand each of the following:

(1) \(\cos (\mathrm{X}-\mathrm{Y})\)

(2) \(\sin \left(\mathrm{A}-20^{\circ}\right)\)

(3) \(\sin \left(2 \alpha+45^{\circ}\right)\)
in Mathematics by Diamond (71,587 points) | 8 views

1 Answer

0 like 0 dislike
(1) \(\cos (X-Y)=\cos X \cdot \cos Y+\sin X \cdot \sin Y\)

(2) \(\sin \left(\mathrm{A}-20^{\circ}\right)=\sin \mathrm{A} \cdot \cos 20^{\circ}-\cos \mathrm{A} \cdot \sin 20^{\circ}\)

(3) \(\sin \left(2 \alpha+45^{\circ}\right)=\sin 2 \alpha \cdot \cos 45^{\circ}+\cos 2 \alpha \cdot \sin 45^{\circ}\)
\[
\begin{aligned}
& =\sin 2 \alpha \cdot\left(\frac{\sqrt{2}}{2}\right)+\cos 2 \alpha \cdot\left(\frac{\sqrt{2}}{2}\right) \\
& =\left(\frac{\sqrt{2}}{2}\right)(\sin 2 \alpha+\cos 2 \alpha)=\frac{\sqrt{2}(\sin 2 \alpha+\cos 2 \alpha)}{2}
\end{aligned}
\]
by Diamond (71,587 points)

Related questions

0 like 0 dislike
0 answers
0 like 0 dislike
0 answers
0 like 0 dislike
0 answers
0 like 0 dislike
0 answers
0 like 0 dislike
0 answers
0 like 0 dislike
1 answer
0 like 0 dislike
1 answer
asked Apr 30, 2020 in Mathematics by MathsGee Platinum (163,814 points) | 132 views
0 like 0 dislike
1 answer
0 like 0 dislike
1 answer
asked Nov 9, 2021 in Mathematics by MathsGee Platinum (163,814 points) | 170 views
0 like 0 dislike
0 answers
asked Jan 21 in Mathematics by MathsGee Platinum (163,814 points) | 8 views
0 like 0 dislike
1 answer
asked Jan 21 in Mathematics by MathsGee Platinum (163,814 points) | 7 views
2 like 0 dislike
1 answer
asked Jan 22 in Mathematics by MathsGee Platinum (163,814 points) | 7 views
0 like 0 dislike
1 answer

Join MathsGee, where you get expert-verified math and data science education support from our community fast.


On the MathsGee, you can:


1. Ask and answer questions


2. Get expert-verified answers


3. Vote on questions and answers


4. Tip your favorite community members


5. Join expert live video sessions (Paid/Free)


6. Earn points by participating


7. Start a Fundraiser



Posting on MathsGee


1. Remember the human


2. Act like you would in real life


3. Find original source of content


4. Check for duplicates before publishing


5. Read the community guidelines




MathsGee Rules


1. Answers to questions will be posted immediately after moderation


2. Questions will be queued for posting immediately after moderation


3. Depending on the number of messages we receive, you could wait up to 24 hours for your message to appear. But be patient as posts will appear after passing our moderation.




MathsGee Android Q&A

MathsGee Android Q&A