Question

Q5. The value of sin 90 sin 60° +cos 60" cos 90° is

Answer 1

Step-by-step explanation:

Sin30+sin60+sin90 ÷ cos30+cos60+cos90?

Trigonometry

1 Answer



BB

Apr 11, 2018

6+7√36

(Are you sure you didn't miss out brackets somewhere? Is this what you meant? sin30+sin60+sin90cos30+cos60+cos90. Because the answer to this is √3 which seems a lot nicer and more likely)

Explanation:

sin30=12

sin60=√32

sin90=1

cos30=√32

cos60=12

cos90=0

Now, you have to follow the order of operations (BIDMAS):

Brackets

Indices

Division

Multiplication

Addition

Subtraction

As you can see, you do division before addition, so you must do sin90cos30 before anything else.

sin90cos30=1√32=2√33

Now add the other values