# Tutor profile: Ananna B.

## Questions

### Subject: Trigonometry

Consider a right-angled triangle right angled at A with angles A, B, C. Find angles B and C such that sin(B) = cos(B).

Draw out the right angled triangle as mentioned in the question in your imagination. Use a pen and paper if necessary. Assume that the length of the side opposite to angle B is denoted by 'b' and that opposite to angle C is denoted by 'c'. Let the length of the hypotenuse be denoted by 'h'. We know that sin(B) = b/h and cos(B) = c/h. sin(B) = cos(B) means b/h = c/h which gives b = c. There you go! The other two sides are equal in length which means the other two angles are 45 degrees each.

### Subject: Basic Math

What is the number of 3-digit numbers divisible by 6?

The answer is 150. There are 900 three digit numbers from 100 to 999 (subtract 100 from 900 and add 1 to include the number 100 itself). The very first number divisible by 6 will be 102 and the last will be 996. Using AP(Arithmetic Progression) where the common difference is 6(every 6th number from 102 will be divisible by 6) we find the number of terms 'n' - 996 = 102 + (n-1)*6 Solving the above equation, n comes out to be 150.

### Subject: C Programming

Given a code fragment as follows: void main() { printf("%d\n",sizeof(printf("Hello World\n"))); } What is the output of the above code, assuming there are no errors in compilation and execution?

What do you think can be the output? It may look like either of these- Hello World 4 or 4 Hello World Well, it is neither! The answer is 4. Why? Anything that is written inside the braces of sizeof() does not matter because it will not get evaluated or executed.Hence Hello World will not be printed anywhere. Now printf() does the job of returning an integer (int) value regarding the number of characters it has printed. The sizeof() expression only evaluated the size of int and the answer is 4.

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