Question

determine the general solution: sin 2x=-1/2

Answer 1

remember sin(7pi/6)=-1/2
and sin(11pi/6)=-1/2
so sin(7pi/6+2npi)=-1/2
and sin(11pi/6+2npi)=-1/2
for n=0,1,2,3,...
so 2x=7pi/6+2npi
and
2x=11pi/6+2npi
solve both of these for x and you are done

Answer 2

let 2x = alpha or beta or theta
sin(a)=-1/2
a=30 degrees right
( taking Sin^-1 * -1/2)

we know using unit circle that sin is negative in 3rd and 4th quad
one angle will be 30 and other will be 330.

as a =2x

2x=30

2x=330

x=15 and x=165

Answer 3

there you have solutions

Answer 4

sin30 is not -1/2

Answer 5

agreed

Answer 6

i think he knew that because he did say look in 3rd and 4th quad he just made mistake

Answer 7

yes,seems to be

Answer 8

uzma am i your fan
i should be your fan
let me look

Answer 9

:P

Answer 10

yep i am

Answer 11

same here;)

Answer 12

i dont know how did i miss it earlier

Answer 13

hopefully u were not making a fun of me :P

Answer 14

lol you will never know
i go to sleep now
goodnight

Answer 15

sorry that was a typing error. buh i did mention it

Answer 16

-> sin 2x=-1/2
-> sin 2x=sin(-pi/6)
-> 2x=n(pi)+(pi/6)(-1)^n where n is integer
(this is a formula,if sin x=sin a ,and ( -pi/2) <= (a ) <=(pi/2) then
x= n(pi) + ( -1) to the power n multiplied by (a) )
-> x=(1/2) *( n(pi)+(pi/6)(-1)^n ) where n is integer .....for values of x just put values of n= ... -3,-2,-1,0,1,2,3....