Find the equation of the straight line which passes through the point (1,2) and makes such an angle with the positive direction of x – axis whose sine is  .
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A line which is passing through (1,2)
To Find: The equation of a straight line.
Formula used: The equation of line is [y – y1 = m(x – x1)]
Explanation: Here, 
We know, 
According to Pythagoras theorem,
(Hypotenuse)2 = (Base)2 + (Perpendicular)2
(5)2 = (Base)2 + (3)2
(Base) = 
(Base)2 = 
Base = 4
Hence, 
SO, The slope of the line, m = tan θ
m = 
The line passing through (x1,y1) = (1,2)
The required equation of line is y – y1 = m(x – x1)
y – 2 =  (x – 1)
 (x – 1)
4y – 8 = 3x – 3
3x – 4y + 5 = 0
Hence, The equation of line is 3x – 4y + 5 = 0