Alright, lets get started.
The answer Sandra got is correct that is zero but there are some mistakes she made while writing steps.
Incorrect step
Because as per even/odd identity,
Cot (-Θ) = - cot (Θ)
Hence

Now,
It could be written as


0
Hence the answer is 0. : Answer
Hope it will help :)
Answer:
1/16
Step-by-step explanation:
Four cards numbered (1, 5, 8,9)
Given the sample space S= 4
1.The first selection with replacement
Probability of picking a 9= 1/4
2. Second selection, probability of picking a 9= 1/4
Hence the probability that both cards drawn have the number 9.
Is = (1/4)*(1/4)= 1/16
Well the total would be -5
Simplify the following:
((8 x^3 y^2 a^2 b^4)/4)^(-2)
8/4 = (4×2)/4 = 2:
(2 x^3 y^2 a^2 b^4)^(-2)
Multiply each exponent in 2 x^3 y^2 a^2 b^4 by -2:
(x^(-2×3) y^(-2×2) a^(-2×2) b^(-2×4))/(2^2)
-2×3 = -6:
(x^(-6) y^(-2×2) a^(-2×2) b^(-2×4))/2^2
-2×2 = -4:
(y^(-4) a^(-2×2) b^(-2×4))/(2^2 x^6)
-2×2 = -4:
(a^(-4) b^(-2×4))/(2^2 x^6 y^4)
-2×4 = -8:
b^(-8)/(2^2 x^6 y^4 a^4)
2^2 = 4:
Answer: 1/(4 x^6 y^4 a^4 b^8) thus the answer is A