If y=mx+c is a tangent to the circle `x^2+y^2=1`, show that `c=+-sqrt(1+m^2)`

The line y=x+1 is a tangent to the curve y^2=4 x at the point a) (1,2) b) (2,1) c) (1,-2) d) (-1,2)

The line y=m x+1 is a tangent to the curve y^2=4x Find the value of m .

The line y = 2x + c is a tangent to the parabola y^(2) = 16x if c equals

If the straight line y-2x+1=0 is the tangent to the curve xy+ax+by=0 at x=1 , then the values of a and b are respectively a) 1and 2 b) 1and -2 c) -1 and 2 d) -1 and -2