IGCSE Mathematics January 2020 - 4MA1/1HR

IGCSE Mathematics January 2020 - 4MA1/1HR

Contents:
00:00 - Intro
00:10 - Question 1
00:56 - Question 2
01:28 - Question 3
02:48 - Question 4
04:04 - Question 5
05:07 - Question 6
05:28 - Question 7
06:12 - Question 8
08:12 - Question 9
09:56 - Question 10
11:19 - Question 11
12:12 - Question 12
14:21 - Question 13
16:34 - Question 14
17:54 - Question 15
19:13 - Question 16
20:58 - Question 17
22:43 - Question 18
24:52 - Question 19
27:05 - Question 20
29:57 - Question 21
33:17 - Question 22
35:53 - Question 23

[nitrogamez]

Hi man, in q21 why do you do 180 - 61.4? why do you not just use 61.4 as the angle that you substitute into the cosine rule equation?

[DylanCombrinck]

Hi, I am confused how you simplified the volume of the small and large cone for question 20 (28:30). I have looked at your previous responses to the same question but I still don't get it.

[HlaNabil-oe]

36:32 why did we make it a zero equation, actually I have understood till the part of V= 3T*2+8T-5 but the rest I didn’t understand it?

[scarletmouse]

hi, for 24:15 why did you take the y of the turning points? doesnt 'solution' mean points where the graph intersects the x axis?

[senseidom]

For Question 21, you found the angle at C to be 61.4 but then you did 180-61.4. Why did you do this?

[farisplayztools]

for question 22. i djdnt understand it at all how did you draw te graph with the red marker what equation did you use

[goalkeeper]

sir, in question 18, why can't you draw a tangent from 0, 0 to point P in order to calculate the gradient?

[LuckyGe]

Hi! Great video as always! I don’t get how you simplified the fractions in Q20 at 28:39, could you please clarify? How is such simplification possible?

[lilrishitherapperofficial]

Hi for Q15 instead of cos40 i did sin40 x 12 is that still acceptable? and then i did pythagoras to get EF as 9.1925

[Dgrking]

Hi, I need help with the topic of trigonometric graphs, have you by any chance made a video explaining how to solve them ?

[youssefeltahawy]

hello, for question 21 i dont understand why you subtract 61.4 from 180

[ShaunDOuttaPocket]

Hey, awesome video, but i didnt understand question 18 part B?

[lilrishitherapperofficial]

Should i write for Q14) 180-76 = 104 Because angles in a triangle add up to 180, or no?

[عليسالم-قسح]

How did u do Pythagorus theorem with abc and its not a right angled triangle

[Hazy-Sky]

Hi, in question 17b) why is the range evolving around the the y coordinate?

[SondosMohammedRawy]

hi!! love the video but at question 18 part c why did u use y=-1 and y=3

[lilrishitherapperofficial]

For Q20, How did you get that after the first line of volume of frusrum

[basedhellas]

how do you find the solutions of an equation ona graph I'm confused.

[lilrishitherapperofficial]

Hi for Q17 What does the x cross equal to -3 mean?

[abx]

In qes 13, how did you get 567 for 990x?