【人教版】九年级下册数学第二十八章 锐角三角函数（二）

sin0°=sin0=0

sin30°=<span class="equation-text" data-index="0" data-equation="{sin π\over 6}" contenteditable="false"><span></span><span></span></span>=<span class="equation-text" contenteditable="false" data-index="1" data-equation="{1\over 2}"><span></span><span></span></span>=0.5

sin45°=<span class="equation-text" contenteditable="false" data-index="0" data-equation="{sin π\over 4}"><span></span><span></span></span>=<span class="equation-text" data-index="1" data-equation="{\sqrt{2}\over 2}" contenteditable="false"><span></span><span></span></span>

sin60°=<span class="equation-text" contenteditable="false" data-index="0" data-equation="{sin π\over 3}"><span></span><span></span></span>=<span class="equation-text" data-index="1" data-equation="{\sqrt{3}\over 2}" contenteditable="false"><span></span><span></span></span>

sin90°=<span class="equation-text" contenteditable="false" data-index="0" data-equation="{sin π\over 2}"><span></span><span></span></span>=1

sin180°=sinπ=0

cos0°=cos0=1

cos30°=<span class="equation-text" contenteditable="false" data-index="0" data-equation="{cos π\over 6}"><span></span><span></span></span>=<span class="equation-text" data-index="1" data-equation="{\sqrt{3}\over 2}" contenteditable="false"><span></span><span></span></span>

cos45°=<span class="equation-text" contenteditable="false" data-index="0" data-equation="{cos π\over 4}"><span></span><span></span></span>=<span class="equation-text" data-index="1" data-equation="{\sqrt{2}\over 2}" contenteditable="false"><span></span><span></span></span>

cos60°=<span class="equation-text" contenteditable="false" data-index="0" data-equation="{cos π\over 3}"><span></span><span></span></span>=1/2

cos90°=<span class="equation-text" contenteditable="false" data-index="0" data-equation="{cos π\over 2}"><span></span><span></span></span>=0

cos180°=cosπ=-1

tan0°=tan0=0

tan30°=<span class="equation-text" contenteditable="false" data-index="0" data-equation="{tan π\over 6}"><span></span><span></span></span>=<span class="equation-text" data-index="1" data-equation="{\sqrt{3}\over 3}" contenteditable="false"><span></span><span></span></span>

tan45°=<span class="equation-text" contenteditable="false" data-index="0" data-equation="{tan π\over 4}"><span></span><span></span></span>=1

tan60°=<span class="equation-text" contenteditable="false" data-index="0" data-equation="{tan π\over 3}"><span></span><span></span></span>=<span class="equation-text" data-index="1" data-equation="\sqrt{3}" contenteditable="false"><span></span><span></span></span>

tan180°=tanπ=0