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2 years ago

If 1-cosA = 1/2 , Then find the value of sinA.

Mathematics

1 answer:

zimovet [89]2 years ago

8 0

Step-by-step explanation:

Given :

1- cosA = 1/2

or, CosA = 1 -1/2

Therefore ; CosA = 1/2 = b/h

According to the Pythagoras theorem,

P = root under h^2 - b^2

= root under (2)^2 - (1)^2

= root under 4 -1

= root 3

Again,

SinA = P/h

= root 3 / 2

You might be interested in

Are the following figures similar?

Tcecarenko [31]

No the corresponding angles are not congruent, because the angle measures on the smaller figure are 90, 90, 137, and 43, while the larger figure has angle measures of 90, 90, 136, 44. that is why the following figures are not congruent.

3 0

3 years ago

Here are two offers for batteries.

trapecia [35]

OFFER A is cheaper.

Step-by-step explanation:

Given,

OFFER A

Pack of 5

£2.75

Pay for 3 packs get 1 free

And

OFFER A

Pack of 5

£2.75

Pay for 3 packs get 1 free

To find which offer is cheaper.

<u>For OFFER A</u>

For 4 Packets he needs to pay £2.75

He needs to buy 40 batteries.

He needs to buy 40÷(4×5) = 2 packets.

Total cost = £2.75 ×2 = £5.5

<u>For OFFER B</u>

For 4 Packets he needs to pay £2.52

He needs to buy 40 batteries.

He needs to buy 10 packets.

After discount he has to pay = £2.52 -(£2.52 × $\frac{1}{3}$ ) = £1.68

Total cost = £1.68×10 = £16.8

Hence,

OFFER A is cheaper.

7 0

3 years ago

2.5% of a population are infected with a certain disease. There is a test for the disease, however the test is not completely ac

Aleks04 [339]

Answer:

$P(disease/positivetest) = 0.36116$

Step-by-step explanation:

This is a conditional probability exercise.

Let's name the events :

I : ''A person is infected''

NI : ''A person is not infected''

PT : ''The test is positive''

NT : ''The test is negative''

The conditional probability equation is :

Given two events A and B :

P(A/B) = P(A ∩ B) / P(B)

$P(B) >0$

P(A/B) is the probability of the event A given that the event B happened

P(A ∩ B) is the probability of the event (A ∩ B)

(A ∩ B) is the event where A and B happened at the same time

In the exercise :

$P(I)=0.025$

$P(NI)= 1-P(I)=1-0.025=0.975\\P(NI)=0.975$

$P(PT/I)=0.904\\P(PT/NI)=0.041$

We are looking for P(I/PT) :

P(I/PT)=P(I∩ PT)/ P(PT)

$P(PT/I)=0.904$

P(PT/I)=P(PT∩ I)/P(I)

0.904=P(PT∩ I)/0.025

P(PT∩ I)=0.904 x 0.025

P(PT∩ I) = 0.0226

P(PT/NI)=0.041

P(PT/NI)=P(PT∩ NI)/P(NI)

0.041=P(PT∩ NI)/0.975

P(PT∩ NI) = 0.041 x 0.975

P(PT∩ NI) = 0.039975

P(PT) = P(PT∩ I)+P(PT∩ NI)

P(PT)= 0.0226 + 0.039975

P(PT) = 0.062575

P(I/PT) = P(PT∩I)/P(PT)

$P(I/PT)=\frac{0.0226}{0.062575} \\P(I/PT)=0.36116$

8 0

3 years ago

What is 121,580 rounded to the nearest thousand?

AfilCa [17]

$121,580\approx122,000$

7 0

3 years ago

Read 2 more answers

The sum of twice a number and 8 is 44. what's the number? show your work.

mezya [45]

Answer:

Step-by-step explanation:

We can work backwards with this and take 44-8=36

Then we divide it by two and thats 18

3 0

3 years ago