# Homework for EEC 243 MatLab, Lab And Assignment

I’m studying and need help with a Computer Science question to help me learn.

# Lab 4: Introduction to MATLAB Programming

## Tasks

• The Pythagorean theorem states that for a right triangle, the relationship between the length of the hypotenuse c and the lengths of the other sides a and b is given by:
• Write a script that will prompt the user for a character.It will create an x-vector that has 50 numbers, equally spaced between -2p and 2p, and then a y-vector which is cos(x).If the user entered the character ‘r’, it will plot these vectors with red *s – otherwise, for any other character it will plot the points with green +s.
• In chemistry, the pH of an aqueous solution is a measure of its acidity.The pH scale ranges from 0 to 14, inclusive.A solution with a pH of 7 is said to be neutral, a solution with a pH greater than 7 is basic, and a solution with a pH less than 7 is acidic.Write a script that will prompt the user for the pH of a solution, and will print whether it is neutral, basic, or acidic.If the user enters an invalid pH, an error message will be printed.
• Write a function called “makemat” that will receive two row vectors as input arguments, and from them create and return a matrix with two rows.You may not assume that the length of the vectors is known.Also, the vectors may be of different lengths.If that is the case, add 0’s to the end of one vector first to make it as long as the other.For example, a call to the function might be:

c2 = a2 + b2

Write a script that will prompt the user for the lengths a and c, call a function findb to calculate and return the length of b, and print the result.Note that any values of a or c that are less than or equal to zero would not make sense, so the script should print an error message if the user enters any invalid value.Here is the function findb:

findb.m

function b = findb(a,c)

% Calculates b from a and c

b = sqrt(c^2 – a^2);

end

>>makemat(1:4, 2:7)

ans =

123400

234567

Hit: use the function zeros() to create a vector of zeros and then append the vector to the vector with shorter length.

• Simplify this statement:
• Simplify this statement:
• The continuity equation in fluid dynamics for steady fluid flow through a stream tube equates the product of the density, velocity, and area at two points that have varying cross-sectional areas.For incompressible flow, the densities are constant so the equation is A1V1 = A2V2 .If the areas and V1 are known,V2 can be found as .Therefore, whether the velocity at the second point increases or decreases depends on the areas at the two points.Write a script that will prompt the user for the two areas in square feet, and will print whether the velocity at the second point will increase, decrease, or remain the same as at the first point.
• Rewrite the following nested if-else statement as a switch statement that accomplishes exactly the same thing.Assume that num is an integer variable that has been initialized, and that there are functions f1, f2, f3, and f4.Do not use any if or if-else statements in the actions in the switch statement, only calls to the four functions.
• Whether a storm is a tropical depression, tropical storm, or hurricane is determined by the average sustained wind speed.In miles per hour, a storm is a tropical depression if the winds are less than 38 mph.It is a tropical storm if the winds are between 39 and 73 mph, and it is a hurricane if the wind speeds are >= 74 mph.Write a script that will prompt the user for the wind speed of the storm, and will print which type of storm it is.

if number > 100

number = 100;

else

number = number;

end

Answer:

if val >= 10

disp(‘Hello’)

elseif val < 10

disp(‘Hi’)

end

Answer:

Answer:

if num < -2 || num > 4

f1(num)

else

if num <= 2

if num >= 0

f2(num)

else

f3(num)

end

else

f4(num)

end

end

Answer:

Answer: