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How do I know when to use le passé simple or l'imparfait ?

In French, both le passé simple and l'imparfait are used for past situations. However, they are not used the same way. Le passé simple is used for short, sudden actions such as : "Out of the blue, she s...
LA
Answered by Lou A. • French tutor
2913 Views

A source of green laser light has a wavelength of 560nm, what is its frequency? Give your answer to an appropriate number of significant figures and using the correct units.

1.) using the wave speed formula for an electromagnetic wave, c=fλ, (c=3.00x10^8 m/s) f=c/λ where c=the speed of an electromagnetic wave. f=(3.00x10^8)/(560x10^-9)= 5.36x10^14 Hz
JE
Answered by Joel E. • Physics tutor
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(1.) f(x)=x^3+3x^2-2x+15. (a.) find the differential of f(x) (b.) hence find the gradient of f(x) when x=6 (c.) is f(x) increasing or decreasing at this point?

(1.) (a.) f’(x)=3x^2+6x-2 (b.) x=6 gradient=142 (c.) since f’(x)>0 at x=6, the function is increasing.
JE
Answered by Joel E. • Maths tutor
4139 Views

The equation x^3 - 3*x + 1 = 0 has three real roots; Show that one of the roots lies between −2 and −1

In order to prove that one real root of an equation is situated in a certain interval, we calculate the value of the function at the ends of the given interval. In the given case, f(-2) = (-2)^3 - 3*(-2) + 1...
PT
Answered by Paul T. • Maths tutor
12655 Views

Complete the square and find the roots (where y=0) of: "x^2+4x-5"

completing the square: (x+2)^2-9 finding the roots: (x+2)^2=9 x+2=+/-3 at y= 0, x= -5 or 1
LQ
Answered by Liam Q. • Maths tutor
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