d2 dx2 Find an equation for the line tangent to the curve at the point defined by the given value of t. Also, find the value of at this point. y=4sin t, t=- The equation â¡ represents the line tangent to the curve at t Type an exact answer, using radicals as needed.) d2 The value of- at t= 2 is 4 (Type an exact answer, using radicals as needed.)