Step-by-step explanation:
A left Riemann sum approximates a definite integral as:

Given ∫₂⁸ cos(x²) dx:
a = 2, b = 8, and f(x) = cos(x²)
Therefore, Δx = 6/n and x = 2 + (6/n) (k − 1).
Plugging into the sum:
∑₁ⁿ cos((2 + (6/n) (k − 1))²) (6/n)
Therefore, the answer is C. Notice that answer D would be a right Riemann sum rather than a left (uses k instead of k−1).
Rectangular form:
z = -2.1213203-2.1213203i
Angle notation (phasor):
z = 3 ∠ -135°
Polar form:
z = 3 × (cos (-135°) + i sin (-135°))
Exponential form:
z = 3 × ei (-0.75) = 3 × ei (-3π/4)
Polar coordinates:
r = |z| = 3 ... magnitude (modulus, absolute value)
θ = arg z = -2.3561945 rad = -135° = -0.75π = -3π/4 rad ... angle (argument or phase)
Cartesian coordinates:
Cartesian form of imaginary number: z = -2.1213203-2.1213203i
Real part: x = Re z = -2.121
Imaginary part: y = Im z = -2.12132034
Answer:
the domain of the function is 1 >= y >=9
Answer:

Step-by-step explanation:
<u>Funciones Trigonométricas</u>
La identidad principal en trigonometría es:

Si sabemos que A es un ángulo agudo (que mide menos de 90°), su seno y coseno son positivos.
Dado que Sen A = 4/5, calculamos el coseno:

Sustituyendo:




Tomando raíz cuadrada:

La tangente se define como:

Substituyendo:


Answer: 27/12=2.25
Pretty simple:)
Step-by-step explanation: