Answers

2014-09-03T19:45:55+05:30
Given that SinA - CosA = 0
⇒ SinA = CosA
⇒ A = 45 degrees

Sin45 = Cos45 =  \frac{1}{ \sqrt{2} }

Sin^4 A + Cos^4 A = ( \frac{1}{ \sqrt{2} })^4 + ( \frac{1}{ \sqrt{2} })^4
 =  \frac{1}{4}+  \frac{1}{4}
  =  \frac{1}{2}
0
2014-09-03T19:47:07+05:30
Sina - cosa=0
⇒ sin a = cos a
sin45 = cos45
sin45 =1/√2
substituting in sin⁴+cos⁴,
(1/√2)⁴ +(1/√2)⁴ =1/4 +1/4
                            =2/4
                            =1/2    
 
1 5 1