# Tutor profile: Rishi A.

## Questions

### Subject: Pre-Calculus

What are two trigonometric identities for cot (angle)?

cot(angle) = cos(angle)/sin(angle) and cot(angle) = 1/tan(angle)

### Subject: Chemistry

Stoichiometry Problem: If 618 grams of NH3 and excess oxygen gas react to produce nitrogen oxide and water, how many moles of nitrogen oxide are formed?

First step: Write out a balanced equation 2 NH3 (aq) + 3 O2 (g) --> 3 H2O (l) + N2O3 (g) Second Step: Take note of what you are starting with and what your are finding In this question, we start out with 618 grams of NH3 and we need to find moles of N2O3 Third Step: Create a dimensional analysis table (cannot be displayed through typing) and solve for what you are finding Answer: 18.14 moles N2O3

### Subject: Algebra

Anna has 6 times as much money as Bob, however if Anna earns $6 and Bob earns $8, Anna will still have 3 times as much money as Bob will have. How much money do Anna and Bob have before and after earning the $6 and $8 respectively?

6x +6 = 3(x+8) x = 6 Anna $: Before = $36 After: $42 Bob $: Before = $6 After = $14

## Contact tutor

needs and Rishi will reply soon.