4. An arch is in the form of a semi-ellipse. It is 8 m wide and 2 m high at the centre. Find the height of the arch at a point 1.5 m from one end.
The equation of the semi-ellipse will be of the form
Now, According to the question,
the length of major axis = 2a = 8
The length of the semimajor axis =2
Hence the equation will be,
Now, at point 1.5 cm from the end, the x coordinate is 4-1.5 = 2.5
So, the height at this point is
Hence the height of the required point is 1.56 m.