Question

OK gonna need some help... Don't remember this!
Find sin 540° + 4(tan150°)(cot120°)

Answer 1

sin 540 = sin 180 = 0

tan 150 = -1 / sqrt(3)

cot 120 = -1 / sqrt(3)

Answer 2

\[0 + 4 \times ( {-1 \over \sqrt{3}} \times {-1 \over \sqrt{3}} )\]
\[4 \times { { -1 \times -1 } \over \sqrt3 \times \sqrt3 }\]
\[4 \times { 1 \over 3 } = { 4 \over 3}\]

Answer 3

Is that how you do it? crazy I would have never got that in a million years.

Answer 4

Simple, i calculate the results for the 3 different goniometric expressions, then feed them into the given formula.
Remember, with math, it's not enough to remember something only for a test. You'll need everything you learn in subsequent tests.

Answer 5

thought tan = 150 would be 30 degrees which is sqrt(3)/3

and cot = 120 would be 60 degrees which is sqrt(3)/3

Answer 6

wouldn't they both be negative as well?

Answer 7

yep, they are, but a negative times a negative is a positive

Answer 8

since sqrt(3)/3 x sqrt(3)/3 = 3/9

and 0 + 4(3/9) = 7/9?

So it would be 7/9

Answer 9

\[\frac{4}{1}\times\frac{3}{9}=\frac{12}{9}=\frac{4}{3}\]