maths.free › Trigonometry › Inverse trigonometric functions

Inverse trigonometric functions

arcsin, arccos, arctan (which angle has this ratio) and their derivatives.

sin is not one-to-one, so its inverse is defined on a restricted range: arcsin returns an angle in [−π/2, π/2], arccos in [0, π], arctan in (−π/2, π/2). Picture it: reflect the sine curve across y = x and keep one branch. Think it: their derivatives are algebraic (1/√(1 − x²), 1/(1 + x²)), which is why they appear as antiderivatives of ordinary fractions.

Delovni primer · derivative of arctan(x)

Differentiate atan(x)

\frac{d}{dx}\left[\operatorname{atan}{\left(x \right)}\right]

Korak po koraku

  1. \frac{d}{dx}\left[\operatorname{atan}{\left(x \right)}\right]

    Start from the derivative to compute.

  2. \frac{1}{x^{2} + 1}

    (arctan u)′ = 1/(1+u²).

Odkrij odgovor
f'(x) = \frac{1}{x^{2} + 1}

Zdaj pa ti. Izberite problem, ali tipkajte ali narišite svojo. Vsak korak, sliko, odgovor skriti, dokler ne vprašate.

Obdrži svoje delo.

Brezplačen račun dodaja opombe o vsaki lekciji, zapis o tem, kar ste končali, vaše rešene težave na enem mestu, in tutor lahko vprašate o tej strani. Sama matematika je odprta za vse, prijavljena ali ne.

Registriraj se Prijava

Simboli, ki se uporabljajo tukaj

Tapnite vsak simbol za popolno opredelitev, sliko in kaj pomeni vsaka črka v njej.

Kako: Inverse trigonometric functions

  1. Start from the derivative to compute.
  2. (arctan u)′ = 1/(1+u²).

Vprašanja, ki jih ljudje sprašujejo

Why radians instead of degrees?

A radian is the angle whose arc equals the radius, so it is a pure ratio rather than an arbitrary 1/360 of a turn. With radians the derivative of sin x is exactly cos x; with degrees a factor of π/180 appears everywhere.

Why does sin x = 1/2 have infinitely many solutions?

Sine repeats every full turn, and within one turn it reaches 1/2 twice (at π/6 and 5π/6). Add any whole number of turns to either and it is still true.

How do I remember the exact values?

Two triangles: the 45-45-90 with sides 1, 1, √2 and the 30-60-90 with sides 1, √3, 2. Every value for 30°, 45° and 60° is a ratio of those sides; symmetry gives the rest of the circle.

Več v Trigonometry