All categories

4 years ago

Verify the identity. cos quanity x plus pi divided by two = -sin x

Mathematics

1 answer:

7nadin3 [17]4 years ago

4 0

Answer:

see below

Step-by-step explanation:

cos ( x+pi/2) = -sinx

We know that

cos(A + B) = cos A cos B - sin A sin B

Let x = A and pi/2 = B

cos x cos pi/2 - sin x sin pi/2 = -sin x

We know cos pi/2 = 0 and sin pi/2 = 1

cos x * 0 - sin x *1 = -sin x

- sin x = - sin x

You might be interested in

In a deck of cards (no jokers), what is the probability of picking a card with a letter on it?

IgorLugansk [536]

Answer: 4/13

Step-by-step explanation:

How many cards are there total? In a deck of cards without Jokers, you have 52 cards.

Now, what cards have a letter on them? These are the aces, kings, queens, and jacks. There are 16 of these cards in the deck total. Four different types, with four of each type (4 * 4 = 16).

We will put the number of desired outcomes (cards with a letter) over the possible outcomes (total cards) to create our probability.

16/52

4/13

4 0

2 years ago

10 have volunteered to help with the preparations for a party. How many ways can Susan assign someone to buy beverages, someone

Lesechka [4]

Answer:

The answer is 720 ways.

Step-by-step explanation:

Total friends who volunteered = 10

Total number of jobs that have to be done = 3

Here order matters, so it is a permutation question.

We can use the formula nPr.

= $\frac{10!}{7!}$

= 720 ways.

The second way to solve this is:

Susan can choose the first person to do a job in 10 ways

Then the second job can be done in 9 ways and the third in 8 ways.

Total becomes = $10\times9\times8=720$ ways

5 0

4 years ago

Mr. Jones drove 480 miles to a business meeting his travel time to the meeting was 8hours and from the meeting was 7.5 hours fin

Dmitry [639]

Speed = distance / time

his travel speed TO the meeting.....
s = 480 / 8 = 60 miles per hr

his travel speed FROM the meeting...
s = 480 / 7.5 = 64 miles per hr

8 0

4 years ago

Read 2 more answers

Rex spent $6.42 at the store. He gave the cashier the money shown above. How much money did Rex get back from the cashier?

cupoosta [38]

The answer is d 10-6.42 is $3.58

4 0

3 years ago

Read 2 more answers

My teacher taught us that we had to flip the fraction to make signs positive, but a friend of mine told me that we mustn’t do th

aivan3 [116]

Answer: