If z is a non - real root of 7√−1, then z86+z175+z289 is equal to:
0
-1
3
1
z = 7√−1 ⇒ z7 = -1
∴ z86+z175+z289=(z7)12z2+(z7)25+(z7)41z2
= (−1)12z2+(−1)25+(−1)41z2
= z2−1−z2 = -1.
Question 13
In the following question, out of the four options, only one is correct. Write the correct answer:
If y be any non-zero integer, then y0 is equal to: (a) 1 (b) 0 (c) -1 (d) Not defined
ΔPQR is right angled at Q. S is the mid-point of QR and PR2=a(PS)2+b(PQ)2
Then a + b is equal to: