Respuesta :
Answer and Step-by-step explanation:
(66) x = 3 sin t, y = 3cos t at t = π/4
dx/dt = 3cos t, dy/dt = - 3sin t
Slope of the tangent, m = dy/dx = (dy/dt)/(dx/dt) = -(sin t)/(cos t) = - tan t = - tan (π/4) = - 1
At this point
x = 3 sin (π/4) = (3√2)/2
y = 3 cos (π/4) = (3√2)/2
Equation of the tangent
(y - ((3√2)/2) = -1(x - (3√2)/2)
y + x = ((3√2)/2) - ((3√2)/2) = 0
y + x = 0
(67) x = cos t, y = 8 sin t, t = π/2
dx/dt = - sin t, dy/dt = 8 cos t
slope, m = dy/dx = (dy/dt)/(dx/dt) = - (8cos t)/(sin t) = -(8 cos (π/2))/(sin (π/2)) = 0
At this point,
x = cos π/2 = 0, y = sin π/2 = 1
Equation of the tangent,
y - 1 = 0(x - 0)
y = 1.
(68) x = 2t, y = t³, t = -1
dx/dt = 2, dy/dt = 3t²
slope, m = dy/dx = (dy/dt)/(dx/dt) = 3t²/2 = 3(-1)²/2 = 3/2
At this point,
x = 2(-1) = -2, y = (-1)³ = -1
Equation of the tangent,
y + 1 = (3/2)(x + 2)
2y - 3x = 4
(69) x = t + (1/t), y = t - (1/t), t = 1
dx/dt = 1 - (1/t²), dy/dt = 1 + (1/t²)
slope, m = dy/dx = (dy/dt)/(dx/dt) = (t² + 1)/(t - 1) = (1+1)/(1-1) = 2/0
At this point, t = 1
x = 2 = -2, y = 0
Equation of the tangent,
y - 0 = (2/0)(x - 2)
x - 2 = 0
x = 2
(70) x = √t, y = 2t, t = 4
dx/dt = -(1/2√t), dy/dt = 2
slope, m = dy/dx = (dy/dt)/(dx/dt) = -4√t = -4√4 = -8
At this point,
x = √4 = 2, y = 2×4 = 8
Equation of the tangent,
y - 8 = - 8(x - 2)
y + 8x = 16
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Answer and Step-by-step explanation:
(66) x = 3 sin t, y = 3cos t at t = π/4
dx/dt = 3cos t, dy/dt = - 3sin t
Slope of the tangent, m = dy/dx = (dy/dt)/(dx/dt) = -(sin t)/(cos t) = - tan t = - tan (π/4) = - 1
At this point
x = 3 sin (π/4) = (3√2)/2
y = 3 cos (π/4) = (3√2)/2
Equation of the tangent
(y - ((3√2)/2) = -1(x - (3√2)/2)
y + x = ((3√2)/2) - ((3√2)/2) = 0
y + x = 0
(67) x = cos t, y = 8 sin t, t = π/2
dx/dt = - sin t, dy/dt = 8 cos t
slope, m = dy/dx = (dy/dt)/(dx/dt) = - (8cos t)/(sin t) = -(8 cos (π/2))/(sin (π/2)) = 0
At this point,
x = cos π/2 = 0, y = sin π/2 = 1
Equation of the tangent,
y - 1 = 0(x - 0)
y = 1.
(68) x = 2t, y = t³, t = -1
dx/dt = 2, dy/dt = 3t²
slope, m = dy/dx = (dy/dt)/(dx/dt) = 3t²/2 = 3(-1)²/2 = 3/2
At this point,
x = 2(-1) = -2, y = (-1)³ = -1
Equation of the tangent,
y + 1 = (3/2)(x + 2)
2y - 3x = 4
(69) x = t + (1/t), y = t - (1/t), t = 1
dx/dt = 1 - (1/t²), dy/dt = 1 + (1/t²)
slope, m = dy/dx = (dy/dt)/(dx/dt) = (t² + 1)/(t - 1) = (1+1)/(1-1) = 2/0
At this point, t = 1
x = 2 = -2, y = 0
Equation of the tangent,
y - 0 = (2/0)(x - 2)
x - 2 = 0
x = 2
(70) x = √t, y = 2t, t = 4
dx/dt = -(1/2√t), dy/dt = 2
slope, m = dy/dx = (dy/dt)/(dx/dt) = -4√t = -4√4 = -8
At this point,
x = √4 = 2, y = 2×4 = 8
Equation of the tangent,
y - 8 = - 8(x - 2)
y + 8x = 16