**Question:** The co-ordinates of a moving particle at time 𝑡 are given by 𝑥 = 𝑐𝑡 2 and 𝑦 = 𝑏𝑡 2 . The instantaneous speed of the particle is

(A) 2𝑡(𝑏 + 𝑐)

(B) 2+\left( b+c\right) ^{1/2}

(C) 2t\left( c^{2}-b^{2}\right)

(D) 2t\left( c^{2}+b^{2}\right) ^{1/2}

**Answer:** option (D)

**Solution:**

*Related*