3 sem maths

Which of the following represents a second-order differential equation?

• d^2y/dx +y= 0

• dy/dx +8y= 0

• d^2y/dx^2 +5y= 0

• d^3y/dx^3 +9y= 0

What is the regression line used for?

• To show the relationship between two variables and make predictions.
• To identify outliers in a dataset
• To determine the mode of a dataset
• To calculate the mean of a dataset

Correlation coefficient is a number between

• 1 and 2
• 0 and 1
• 2 and 3
• -1 and 1

We can use rank correlation when

• When we want to measure the relationship between three variables
• When we want to measure the relationship between two variables based on the ranks of the values rather than the actual values themselves.
• When we want to measure the relationship between categorical and numerical variables
• When we want to measure the relationship between two variables using linear regression

In a binomial distribution if mean=4 and n =10 what is the probability of failure q?

• 0.6

• 0.2
• 0.0

• 0.8

What are the values of mean and standard deviation in a standard normal distribution?

• Mean = 0, Standard Deviation = 0.5

• Mean = 1, Standard Deviation = 0
• Mean = 1, Standard Deviation = 1
• Mean = 0, Standard Deviation = 1

The Fourier series is used to represent the given function as

• Division of sines and cosines
• Sum of sines and cosines
• Product of sines and cosines
• Exponential functions

Z- transform of 2+n is

• 2(z)/(z-1)

• (2z-1)/z

• (2+z)(z-1)^2

• (2z^2-z)/(z-1)^2

Inverse z- transform of z/(z^2+1) is

• e^{nt}

• sin(n*pi/2)

• n^2

• cos(n*pi/4)

In Fourier series expansion , a0 value when f(x)=x in(-pi pi) is

• 0

• pi/2

• (2pi^2)/2

• 2π