Question

tan(-3pie/2)

Answer 1

infinity

Answer 2

and its pi not pie

Answer 3

oh my bad.thanks.

Answer 4

although at mit they celbrate pi day by having pie...

Answer 5

thats funny

Answer 6

wait...how did you get infinity?. we are suppose to use the unit circle.

Answer 7

the x coordinate of a point on the unit circle is cosine isnt it? and the y-coordinate is sine\?? so when you divide them u get tan..for -3pi/2 y=1, x=0

Answer 8

as u can use the same values for -3pi/2 and pi/2

Answer 9

get it??

Answer 10

so tan would not be 1/0 and make it undefined?

Answer 11

yeah...infinity

Answer 12

or you can say tending to infinity

Answer 13

oh..ok thanks!

Answer 14

are you busy because I had 3 other similar ones?

Answer 15

fire away bt i wont answer straightaway..u need to learn

Answer 16

ok good..csc5pi

Answer 17

try....wts cosec defined AS?

Answer 18

its 1/y

Answer 19

wts y?

Answer 20

0?

Answer 21

how?

Answer 22

because 5pi-2pi=3pi then 3pi-2pi=pi so the y value of pi is 0

Answer 23

yeah ur right..so wts ur final answer?

Answer 24

so 1/0 which means its undefined or infinity

Answer 25

right

Answer 26

ok. next one is sec(-pi/4)

Answer 27

go the same way...sec is dfined as?

Answer 28

1/x and x is \[\sqrt{2}/2\]

Answer 29

yes

Answer 30

so 1/sqrt{2}/2 then i rationalize and get sqrt2/2?

Answer 31

u just cancel one sqrt 2 and get 1/sqrt(2)

Answer 32

so then sec is 1/x, so sec is sqrt(2)

Answer 33

oh ok

Answer 34

and does it matter if it is - pi?

Answer 35

not in this case bcoz cos(-pi) = cos(pi)

Answer 36

or infact cos(x) = cos(-x)

Answer 37

so it does not make a difference

Answer 38

not here...

Answer 39

ok is cot(-4pi/3) equal to 1/sqrt3

Answer 40

-1/sqrt(3)

Answer 41

ok so in this case it would be - i see.

Answer 42

look at the unit circle...-4pi/3 lies in the second quadrant...here cos is -ve and sin is +ve so the ratio is negative..look at it this way

Answer 43

just imagine the unit circle in ur head and ull solve everythng

Answer 44

isnt it in the third quadrant?..and ok i will just memorize

Answer 45

second....just swing ur radius 240 degrees clockwise from the +ve x-axis

Answer 46

oh ok because its -

Answer 47

thanks so much for your help!

Answer 48

welcome

Answer 49

just to add my 2 cents on a saturday, \[\frac{1}{0}\] is undefined. it is not not i repeat not infinity

Answer 50

from your very example here you have
\[\tan(-\frac{3\pi}{2})\] which, if you just plug in the numbers would give
\[\frac{-1}{0}\] and this certainly does't tend to infinity as x approaches
\[\frac{-3\pi}{2}\] because from on direction tangent would increase with out bound to \[\infty\] but from the other direction it would go to
\[-\infty\]

Answer 51

just thought i would mention it