Question

Find the missing coordinate of , using the fact that lies on the unit circle in the given quadrant.
P(?,1/13) quadrant 11
P(2/3,?) quadrant 1

Answer 1

like that, see attachment

Answer 2

use pythagorean theorem
for unit circle radius always equals 1
x^2 + (1/13)^2 = 1
solve for x
the quadrant will tell you whether its pos or neg

Answer 3

so what would be the first one?

Answer 4

x^2 = 1 - (1/13)^2
solve for x

quad 2 means x is neg

Answer 5

for x i got approximatly .9970 but how would i put that in fraction form?

Answer 6

1/13 ^2 = 1/169
1 = 169/169

--> 169/169 - 1/169 = 168/169
x^2 = 168/169
x = sqrt168/13 = 2sqrt42/13

Answer 7

and it will be negative bec its the 2nd quadrant right?

Answer 8

yes

Answer 9

and what about the second one?

Answer 10

x = sqrt ( 1 - 1/169) = - sqrt (168)/ 13
=>( - sqrt (168)/ 13 , 1/13)

y = sqrt ( 1 - 4/9) = sqrt (5)/3
=> ( 2/3, sqrt (5)/3)