Trig Q 2

If 3pi/4<A<pi then √2cotA+cosec²A is equal to ???

6 Answers

is it

(-âˆž,0)?

1357

Manish Shankar ·2009-04-19 03:18:08

z=2cotA+cosec²A=2cotA+1+cot²A=(1+cotA)²

âˆšz=âˆš(1+cotA)²=|1+cotA|

for the given domain

it is -1-cotA

-1-cotA

manish bhaiya can u xplain last step

1357

Manish Shankar ·2009-04-19 03:31:50

|1+cotA|=1+cotA when 1+cotA>0
=-(1+cotA) when 1+cotA<0

in the given domain cotA<-1 so 1+cotA<0

hence the answer

and y does 1+ cotA come under modulus after taking square root??

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