# Tutor profile: Harsh M.

## Questions

### Subject: Trigonometry

If sinx - cosx = (7/13) . Then sinx + cosx = ?

sinx - cosx = 7/13; squaring on both sides (sinx)^2 + (cosx)^2 - 2*sinx*cosx = 49/169; since (sinx)^2 + (cosx)^2 = 1; 1 - (49/169) = 2sinx*cosx; Now let y = sinx + cosx; squaring on both sides y^2 = (sinx)^2 + (cosx)^2 + 2*sinx*cosx ------------------1 since 2sinx*cosx = 1 - (49/169) and (sinx)^2 + (cosx)^2 = 1; putting in equation 1 gives y^2 = 2 - (49/169); y^2 = 289/169; y = 17/13; Hence sinx + cosx = 17/13

### Subject: Chemistry

Which is the most reactive element in the periodic table?

Fluorine is the most reactive nonradioactive element on the periodic table. It exists in gaseous form at room temperature and even reacts with glass. So it is almost impossible to store it in pure form

### Subject: Algebra

Solve these equations:- x+3y=5 4x+7y=15

x=5-3y putting value of x in second equation 4(5-3y)+7y=15; 20-12y+7y=15; 5y=5; y=1; putting value of y in first equation x+3*1=5; x=2; Therfore values of x and y are 2 and 1 respectively.

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