// Numbas version: exam_results_page_options {"name": "Blathnaid's copy of Simplify logarithms", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"variables": {"d": {"group": "Ungrouped variables", "definition": "s4*random(2..9)", "templateType": "anything", "name": "d", "description": ""}, "s4": {"group": "Ungrouped variables", "definition": "random(1,-1)", "templateType": "anything", "name": "s4", "description": ""}, "s1": {"group": "Ungrouped variables", "definition": "random(1,-1)", "templateType": "anything", "name": "s1", "description": ""}, "f": {"group": "Ungrouped variables", "definition": "precround((a2-1)/b2,0)", "templateType": "anything", "name": "f", "description": ""}, "a1": {"group": "Ungrouped variables", "definition": "s1*random(2..9)", "templateType": "anything", "name": "a1", "description": ""}, "b1": {"group": "Ungrouped variables", "definition": "random(2..15)", "templateType": "anything", "name": "b1", "description": ""}, "a2": {"group": "Ungrouped variables", "definition": "1+b2*random(2..5)", "templateType": "anything", "name": "a2", "description": ""}, "b2": {"group": "Ungrouped variables", "definition": "random(2..9)", "templateType": "anything", "name": "b2", "description": ""}, "c": {"group": "Ungrouped variables", "definition": "random(1..9)", "templateType": "anything", "name": "c", "description": ""}}, "name": "Blathnaid's copy of Simplify logarithms", "functions": {}, "tags": [], "metadata": {"description": "\n \t\t
Express $\\log_a(x^{c}y^{d})$ in terms of $\\log_a(x)$ and $\\log_a(y)$. Find $q(x)$ such that $\\frac{f}{g}\\log_a(x)+\\log_a(rx+s)-\\log_a(x^{1/t})=\\log_a(q(x))$
\n \t\t\n \t\t", "licence": "Creative Commons Attribution 4.0 International"}, "statement": "
Find $\\alpha$ and $\\beta$.
\n", "extensions": [], "variablesTest": {"maxRuns": 100, "condition": ""}, "ungrouped_variables": ["c", "d", "f", "s1", "s4", "a1", "a2", "b1", "b2"], "preamble": {"js": "", "css": ""}, "variable_groups": [], "advice": "The rules for combining logs are
\n\\[\\begin{eqnarray*} \\log_a(bc)&=&\\log_a(b)+\\log_a(c)\\\\ \\\\ \\log_a\\left(\\frac{b}{c}\\right)&=&\\log_a(b)-\\log_a(c)\\\\ \\\\ \\log_a(b^r)&=&r\\log_a(b) \\end{eqnarray*} \\]
\na)
Using these rules gives:
\\[ \\begin{eqnarray*} \\log_a(x^{\\var{a1}}y^{\\var{b1}})&=&\\log_a(x^{\\var{a1}})+\\log_a(y^{\\var{b1}})\\\\ &=&\\var{a1}\\log_a(x)+\\var{b1}\\log_a(y) \\end{eqnarray*} \\]
b)
\\[\\begin{eqnarray*} \\simplify[std]{{a2}/{b2}}\\log_a(x)+\\log_a(\\simplify{{c}*x+{d}})-\\log_a(\\simplify{x^(1/{b2})})&=&\\log_a(x^\\frac{\\var{a2}}{\\var{b2}})+\\log_a(\\simplify{{c}*x+{d}})-\\log_a(\\simplify{x^(1/{b2})})\\\\ \\\\ &=&\\log_a\\left(\\simplify[std]{(x^({a2}/{b2})*({c}x+{d}))/(x^(1/{b2}))}\\right)\\\\ &=&\\log_a\\left(\\simplify{x^{f}*({c}x+{d})}\\right) \\end{eqnarray*} \\]
\\[\\log_a(x^{\\var{a1}}y^{\\var{b1}})=\\alpha\\log_a(x)+\\beta\\log_a(y)\\]
\n$\\alpha=\\;\\;$[[0]], $\\beta=\\;\\;$[[1]]
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