Derivative of Planck's spectral distribution

[CricK0es]

Homework Statement

From differentiating Planck's distribution and setting it equal to 0 I've reached the equation below. But now I'm asked to estimate the solution for a/λ. It's suggested that we try to do it graphically/trial and error as it's tricky to do analytically.

I'm wondering how I would go about doing it graphically; I feel like I'm missing something...

Any help would be appreciated, many thanks

Homework Equations

http://www.sciweavers.org/upload/Tex2Img_1488126559/render.png

a = hc/K_bT

The Attempt at a Solution

I did try rearranging to get it in the form:

http://www.sciweavers.org/upload/Tex2Img_1488126973/render.png , But again I'm unsure how I can obtain something useful (graphically I mean)
[/B]

 

[PeroK]

Homework Statement

From differentiating Planck's distribution and setting it equal to 0 I've reached the equation below. But now I'm asked to estimate the solution for a/λ. It's suggested that we try to do it graphically/trial and error as it's tricky to do analytically.

I'm wondering how I would go about doing it graphically; I feel like I'm missing something...

Any help would be appreciated, many thanks

Homework Equations

http://www.sciweavers.org/upload/Tex2Img_1488126559/render.png

a = hc/K_bT

The Attempt at a Solution

I did try rearranging to get it in the form:

http://www.sciweavers.org/upload/Tex2Img_1488126973/render.png , But again I'm unsure how I can obtain something useful (graphically I mean) [/B]

What about looking at the intersection of a line and an exponential?

 

[CricK0es]

Ohhh... I see. Thank you