1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
madam [21]
3 years ago
6

If cosA=3√2/5,then show that cos2A=11/25

Mathematics
1 answer:
Kobotan [32]3 years ago
4 0

Answer:

Step-by-step explanation:

Cos 2A = 2Cos² A - 1

             = 2*(\frac{3\sqrt{2}}{5})^{2}-1\\\\=2*(\frac{3^{2}*(\sqrt{2})^{2}}{5^{2}})-1\\\\=2*\frac{9*2}{25} - 1\\\\=\frac{36}{25}-1\\\\=\frac{36}{25}-\frac{25}{25}\\\\=\frac{11}{25}

You might be interested in
Solve for b.<br><br> −1/3b=9<br><br> What is the answer?
Ksivusya [100]
-1/3b = 9
b = 9 * -3
b = -27
5 0
3 years ago
Read 2 more answers
Sheila is climbin on a latter that is attached against the side of a jungle gym.she is 5 feet off the ground and 3 feet horizont
Zinaida [17]
I didnt get the question quite right if its asking how high the ladder is its 10 ft if its asking about the wall its i think its 20 ft
6 0
3 years ago
Y+4/12-y-1/12=y/2<br><br> Pls! on a time limit
icang [17]

Answer:

y= 1/2

Step-by-step explanation:

5 0
3 years ago
Read 2 more answers
What is.... 36 + 25.2 + 180? :)
Marysya12 [62]

The answer would be 241.2

5 0
3 years ago
Read 2 more answers
1. f(6) if f(x) = 4x I know the answer I just need the explanation please thank you!
suter [353]
So when you have one of these, it’s just asking you so solve it as if x were 6 (as you see where the x in f(x) is replaced with a 6.

so you’d sub x for 6

giving you:

4 x (6)

which = 24

hope that makes sense :)
6 0
3 years ago
Read 2 more answers
Other questions:
  • In a random sample of egg cartons, a supermarket finds that 3 cartons in every 50 cartons contain cracked eggs. If the supermark
    10·1 answer
  • Quick Algebra questions please :)
    6·1 answer
  • 2 Solve the equation for x: 3x – 5 = 5x + 2x.<br> Show your work.
    12·1 answer
  • Devin has -$3.20 in his bank account and then deposits $15.00. What is Devin’s new bank account balance?
    12·1 answer
  • Mary wants to fill in a cylinder vase. At the flower store they told her that the vase should be filled for the flowers to last
    9·1 answer
  • 1. The scores from a statistics test were
    5·1 answer
  • Ten years from now, Abdul will be twice as old as his son pavel ten years ago, Abdul was seven times as old as pavel how old are
    15·1 answer
  • A new building is being constructed a distance of 420 feet from the ocean, and the builder wants to have a rooftop patio
    11·1 answer
  • Someone help please ASAP!!! 15 points available
    8·2 answers
  • If P(A) = 1/10 , find P(A)
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!