Enable contrast version

# Tutor profile: Q A.

Inactive
Q A.
Math tutor
Tutor Satisfaction Guarantee

## Questions

### Subject:Trigonometry

TutorMe
Question:

Prove that: $$[cos(x) - sin(x) ][ cos(2x) - sin(2x) ] = cos(x) - sin(3x)$$

Inactive
Q A.

Right side: $$cos(x) - sin(3x)$$ = $$cos(x) - sin( x + 2x)$$ = $$cos(x) - sin(x)cos(2x) - cos(x)sin(2x)$$ Left side: $$[cos(x) - sin(x) ][ cos(2x) - sin(2x)]$$ = $$cos(x) cos(2x) - cos(x) sin(2x) - sin(x) cos(2x) + sin(x) sin(2x)$$ = $$cos(x)(1 - 2 sin2) + sin(x) 2 sin(x) cos(x) - cos(x) sin(2x) - sin(x) cos(2x)$$ = $$cos(x) - 2 cos(x) sin2 + 2 cos(x) sin2 - cos(x) sin(2x) - sin(x) cos(2x)$$ = $$cos(x) - cos(x) sin(2x) - sin(x) cos(2x)$$ = left side

### Subject:Geometry

TutorMe
Question:

ABC is a right triangle. $$\widehat{BAC}$$ equals 90 degrees. AH is perpendicular to BC ( H is on BC). $$\widehat{ABC}$$ is equal to 60 degrees. Find the size of $$\widehat{HAC}$$ ?

Inactive
Q A.

The sum of all angles in triangle ABH is equal to 180°, so: $$\widehat{ABH}$$ + $$\widehat{BAH}$$ + 90° = 180° Substitute angle ABH by 60 and solve for angle BAH: $$\widehat{BAH}$$ = 180 - 90 - 60 = 30° However, $$\widehat{BAH}$$ + $$\widehat{HAC}$$ = $$\widehat{BAC}$$ = 90° $$\widehat{HAC}$$= $$\widehat{BAC}$$ - $$\widehat{BAH}$$ = 90° - 30° = 60°

### Subject:Calculus

TutorMe
Question:

Calculate indefinite integral: $$\int \sin ^{2}{t}\,dt\,$$

Inactive
Q A.

$$\int \sin ^{2}{t}\,dt\,$$ = $$\int {{(\frac {1}{2}}-{\frac {\cos 2t}{2}})dt}$$ = $$\int {{\frac {1}{2}}dt}-\int {{\frac {\cos 2t}{2}}dt}$$ = $${\frac {t}{2}}-{\frac {\sin 2t}{4}}$$ + C

## Contact tutor

Send a message explaining your
needs and Q will reply soon.
Contact Q

Start Lesson

## FAQs

What is a lesson?
A lesson is virtual lesson space on our platform where you and a tutor can communicate. You'll have the option to communicate using video/audio as well as text chat. You can also upload documents, edit papers in real time and use our cutting-edge virtual whiteboard.
How do I begin a lesson?
If the tutor is currently online, you can click the "Start Lesson" button above. If they are offline, you can always send them a message to schedule a lesson.
Who are TutorMe tutors?
Many of our tutors are current college students or recent graduates of top-tier universities like MIT, Harvard and USC. TutorMe has thousands of top-quality tutors available to work with you.
BEST IN CLASS SINCE 2015
TutorMe homepage