Question

tan225+sin240cos60

Answer 1

Method without using calculator?

Answer 2

@Grazes Have you studied the values of trigonometric ratios in different quadrants?

Answer 3

Yes.

Answer 4

what's tan 225?
I'll give you a hint, write it as \(\tan(180+45)\)

Answer 5

Is it 0+1 or 1?

Answer 6

We know that tan is positive in third quadrant so
\[\tan(180+x)=\tan x\]
so
\[\tan (180+45)=\tan 45\]

Answer 7

My bad. I calculate tan180+tan45

Answer 8

Do you get my point?

Answer 9

Yes.

Answer 10

So sin240 is equal to sin60 but it's is negative in the 3rd quadrant?

Answer 11

Would it be\[1+ (-\frac{ \sqrt{3} }{ 2 }\times \frac{ 1 }{ 2 })\]

Answer 12

yes , you are right :D
Good work

Answer 13

Thanks.