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If A =130 degrees and x= sin A + cos A THEN

(A) X>0 (B) X<0 (C) X=0 (D) X<=0

eXPLAIN PLS...ANS GIVEN IS (A)...

Aditi Bhatnagar , 13 Years ago
Grade 12th Pass
anser 2 Answers
omi more

Last Activity: 13 Years ago

x= sin(130) +cos(130)= sin 70* + (-cos 70*)    =>x>0 (since sin 70* would be greater than cos 70*)

Venkat

Last Activity: 5 Years ago

X= Sin130 + Cos130 =Sin(180-50) + Cos(180-50)
                                     =Sin50 - Cos50
                                     =Sin50 - Cos(90-40)
                                     =Sin50 - Sin40
                                     =Sin(45+5) - Sin(45-5)
                                     =2Cos45.Sin5 
                    Since, the value of 2cos45.sin5 is positive 
                         the value of X is also positive. 

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