The sum is
Step-by-step explanation:
First term(a) = 1
Common difference(d)=2-1=1
No.of term(n)=50
Sn=n÷2(n+1)=50÷2(50+1)=1275
Answer:
Option B
Option C
Step-by-step explanation:
⇒ , which is a real number.
Similarly,
And we also know that
So, we see that odd powers of is a complex number and even powers renders us a real number.
Using this we solve the problem.
Option A: 11 is an odd power. This would be a complex number and not a real number.
Option B: Even power of i. So, this should give us a real number.
Option C:
(a + bi)² = a² - b² + 2abi
So, (2 + 3i)² would be a complex number because of the 2bi term.
Option D: (4 + 5i)(4 - 5i)
(a + ib)(a - ib) = a² + b²
So, (4 + 5i)(4 - 5i) = 4² + 5² = 41, a real number.
Option E: (6 + 8i)(8 + 6i)
(a + ib)(c + id) = ac - bd + (ad + bc)i
This would be a complex number because of the (ad + bc) term.
So, Options B and D are real numbers.
30°
B.
45°
60°
D.
90°