Question

Trigo help please!!

Answer 1

If tanA=-1/2 ,tanB=-1/3,then A+B=?
A)pi/4
B)3pi/4
C)5pi/4
D)None of these

Answer 2

D i think

Answer 3

yea..why

Answer 4

well it should be

-arctan(1/2)-arctan(1/3) as your answer

Answer 5

A = -arctan(1/2), B = -arctan(1/3),
therefore
x = -arctan(1/2)-arctan(1/3)

Answer 6

\[\LARGE \tan(A+B)=\frac{tanA+tanB}{1-tanAtanB}\]
\[\LARGE \frac{\frac{-1}{2}-\frac{1}{3}}{1-\frac{1}{6}} \]
\[\LARGE (A+B)=\frac{3\pi}{4}\]
how do we decide after this?

Answer 7

it is not tan(a+b) it is
a+b

Answer 8

so what..im taking tan of that function

Answer 9

ook

Answer 10

i am also getting 3pi/4
it should work.

Answer 11

its not 3pi/4 but..its D only..answer is 7pi/4

Answer 12

tan (-pi/4) = tan (3pi/4) = tan (7pi/4 ) = -1

Answer 13

yeah but answer is D :P

Answer 14

3pi/4 is not acceptable..:/

Answer 15

the simple ans.
\[\frac{\pi}{2}<A,B<\pi\] or \[\frac{3\pi}{2}<A,B<2\pi\]
so (A+B) must not be \(\frac{3\pi}{4}\)

Answer 16

@shubhamsrg !!!