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Date May 2021 Marks available 7 Reference code 21M.1.AHL.TZ2.2
Level Additional Higher Level Paper Paper 1 (without calculator) Time zone Time zone 2
Command term Solve Question number 2 Adapted from N/A

Question

Solve the equation 2cos2x+5sinx=4, 0x2π.

Markscheme

attempt to use cos2x=1-sin2x              M1

2sin2x-5sinx+2=0                   A1

 

EITHER

attempting to factorise              M1

(2sinx1)(sinx2)                   A1

 

OR

attempting to use the quadratic formula            M1

sinx=5±52-4×2×24=5±34         A1

 

THEN

sinx=12           (A1)

x=π6,5π6                  A1A1

 

[7 marks]

Examiners report

[N/A]

Syllabus sections

Topic 3— Geometry and trigonometry » SL 3.8—Solving trig equations
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Topic 3— Geometry and trigonometry

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