Question

sin2x = cosx
1. give general solutions??
2. solve for x [-360;360]

Answer 1

2sinx = 1 ... if you insist on dividng

Answer 2

sinx=1/2 yes.... u are right.... amistre

Answer 3

and assuming that sin(2x) as opposed to the copy/paste version of sin^2(x)

Answer 4

plzzzzz explain in detail?

Answer 5

the detail is sin(2x) has an identity in terms of cos(x); so use it ....

Answer 6

if its sin^2 (x), then use 1-cos^2 (x) and solve a quadratic

Answer 7

could u plz saw me steps of doing it?

Answer 8

you mean write out a detailed script that covers everything that you can then just copy and paste? no

Answer 9

i am realy struggling with it????

Answer 10

please ask questions about what you do not understand instead of asking for some full solutions

how have you started it, what have you tried in working with it .... what is your effort in this?

Answer 11

x = 150 +360k is my answer???

Answer 12

* and .. the material that you posted is vague and ambiguous due to people breaking form and typing exponents without the "^"

Answer 13

that does not show us any of your workings ... that seems more like you have some options and are guessing at them.

Answer 14

but, it does seem about right ... sin(30) = 1/2; and sin(150) = sin(30)

but that is not the only solution; since cos(x) = 0 when 2sin(x)cos(x) = 0

Answer 15

cosx(2sin-1)=0

Answer 16

when does cos(x) = 0?

Answer 17

x =90 +180k

Answer 18

good, now theres just one more solution set to worry about i believe

Answer 19

notice when i said that sin(150) = sin(30) ?

Answer 20

150+360

Answer 21

yeah, but that 150 + 36ok only covers every 150 .... we are missing the 30s

Answer 22

how?

Answer 23

does 150 = 30?

Answer 24

explain this?

Answer 25

.... does sin(150) = sin(30) ???

Answer 26

yes

Answer 27

are they the same angle? or just the same sin values?

Answer 28

yes 1/2

Answer 29

that doesnt answer my question ....

Answer 30

is the angle 150 equal to the angle 30?